781389056 has 72 divisors (see below), whose sum is σ = 1795940160. Its totient is φ = 332365824.

The previous prime is 781389047. The next prime is 781389067. The reversal of 781389056 is 650983187.

It is a happy number.

It is a super-2 number, since 2×781389056² = 1221137713673142272, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 781389056.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 247520 + ... + 250656.

Almost surely, 2^781389056 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 781389056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (897970080).

781389056 is an abundant number, since it is smaller than the sum of its proper divisors (1014551104).

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

781389056 is a wasteful number, since it uses less digits than its factorization.

781389056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3299 (or 3285 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 47.

The square root of 781389056 is about 27953.3371174177. The cubic root of 781389056 is about 921.0625153313.

It can be divided in two parts, 7813 and 89056, that added together give a palindrome (96869).

The spelling of 781389056 in words is "seven hundred eighty-one million, three hundred eighty-nine thousand, fifty-six".