781956 has 72 divisors (see below), whose sum is σ = 2358720. Its totient is φ = 213696.

The previous prime is 781951. The next prime is 781961. The reversal of 781956 is 659187.

It is an interprime number because it is at equal distance from previous prime (781951) and next prime (781961).

It is a super-2 number, since 2×781956² = 1222910371872, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 781956.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 781956.

It is not an unprimeable number, because it can be changed into a prime (781951) by changing a digit.

781956 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7255 + ... + 7361.

It is an arithmetic number, because the mean of its divisors is an integer number (32760).

2⁷⁸¹⁹⁵⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 781956, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1179360).

781956 is an abundant number, since it is smaller than the sum of its proper divisors (1576764).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

781956 is a wasteful number, since it uses less digits than its factorization.

781956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153 (or 148 counting only the distinct ones).

The product of its digits is 15120, while the sum is 36.

The square root of 781956 is about 884.2827602074. The cubic root of 781956 is about 92.1285223264.

It can be divided in two parts, 7819 and 56, that added together give a triangular number (7875 = T₁₂₅).

The spelling of 781956 in words is "seven hundred eighty-one thousand, nine hundred fifty-six".