78405656 has 32 divisors (see below), whose sum is σ = 171188640. Its totient is φ = 32967168.

The previous prime is 78405637. The next prime is 78405659. The reversal of 78405656 is 65650487.

It is a super-2 number, since 2×78405656² = 12294893785580672, which contains 22 as substring.

It is a Smith number, since the sum of its digits (41) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78405659) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10241 + ... + 16176.

It is an arithmetic number, because the mean of its divisors is an integer number (5349645).

Almost surely, 2^78405656 is an apocalyptic number.

It is an amenable number.

78405656 is an abundant number, since it is smaller than the sum of its proper divisors (92782984).

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

78405656 is a wasteful number, since it uses less digits than its factorization.

78405656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26483 (or 26479 counting only the distinct ones).

The product of its (nonzero) digits is 201600, while the sum is 41.

The square root of 78405656 is about 8854.6968327549. The cubic root of 78405656 is about 428.0052842391.

The spelling of 78405656 in words is "seventy-eight million, four hundred five thousand, six hundred fifty-six".