781345656 has 256 divisors, whose sum is σ = 2700902400. Its totient is φ = 203793408.

The previous prime is 781345603. The next prime is 781345667. The reversal of 781345656 is 656543187.

781345656 is a `hidden beast` number, since 7 + 81 + 3 + 4 + 565 + 6 = 666.

781345656 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×781345656² = 1221002068300140672, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2496156 + ... + 2496468.

It is an arithmetic number, because the mean of its divisors is an integer number (10550400).

Almost surely, 2^781345656 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 781345656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1350451200).

781345656 is an abundant number, since it is smaller than the sum of its proper divisors (1919556744).

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

781345656 is a wasteful number, since it uses less digits than its factorization.

781345656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 475 (or 465 counting only the distinct ones).

The product of its digits is 604800, while the sum is 45.

The square root of 781345656 is about 27952.5608129202. The cubic root of 781345656 is about 921.0454624292.

The spelling of 781345656 in words is "seven hundred eighty-one million, three hundred forty-five thousand, six hundred fifty-six".