78956640 has 288 divisors, whose sum is σ = 322328160. Its totient is φ = 17998848.

The previous prime is 78956627. The next prime is 78956641. The reversal of 78956640 is 4665987.

78956640 is a `hidden beast` number, since 7 + 89 + 566 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78956641) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 211494 + ... + 211866.

It is an arithmetic number, because the mean of its divisors is an integer number (1119195).

Almost surely, 2^78956640 is an apocalyptic number.

78956640 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78956640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (161164080).

78956640 is an abundant number, since it is smaller than the sum of its proper divisors (243371520).

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

78956640 is a wasteful number, since it uses less digits than its factorization.

78956640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 411 (or 390 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 45.

The square root of 78956640 is about 8885.7548919605. The cubic root of 78956640 is about 429.0055258714.

It can be divided in two parts, 7895 and 6640, that added together give a triangular number (14535 = T₁₇₀).

The spelling of 78956640 in words is "seventy-eight million, nine hundred fifty-six thousand, six hundred forty".