781872 has 80 divisors (see below), whose sum is σ = 2499840. Its totient is φ = 205056.

The previous prime is 781867. The next prime is 781883. The reversal of 781872 is 278187.

It is a super-2 number, since 2×781872² = 1222647648768, which contains 22 as substring.

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

It is a nude number because it is divisible by every one of its digits.

It is an alternating number because its digits alternate between odd and even.

It is an unprimeable 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 15 ways as a sum of consecutive naturals, for example, 4279 + ... + 4457.

It is an arithmetic number, because the mean of its divisors is an integer number (31248).

2⁷⁸¹⁸⁷² 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 781872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1249920).

781872 is an abundant number, since it is smaller than the sum of its proper divisors (1717968).

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

781872 is a wasteful number, since it uses less digits than its factorization.

781872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210 (or 204 counting only the distinct ones).

The product of its digits is 6272, while the sum is 33.

The square root of 781872 is about 884.2352628119. The cubic root of 781872 is about 92.1252233032.

It can be divided in two parts, 781 and 872, that added together give a triangular number (1653 = T₅₇).

The spelling of 781872 in words is "seven hundred eighty-one thousand, eight hundred seventy-two".