78706640 has 40 divisors (see below), whose sum is σ = 183419808. Its totient is φ = 31409280.

The previous prime is 78706633. The next prime is 78706657. The reversal of 78706640 is 4660787.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 78706594 and 78706603.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 44819 + ... + 46541.

Almost surely, 2^78706640 is an apocalyptic number.

It is an amenable number.

78706640 is an abundant number, since it is smaller than the sum of its proper divisors (104713168).

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

78706640 is a wasteful number, since it uses less digits than its factorization.

78706640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2307 (or 2301 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 38.

The square root of 78706640 is about 8871.6762790354. The cubic root of 78706640 is about 428.5522611534.

The spelling of 78706640 in words is "seventy-eight million, seven hundred six thousand, six hundred forty".