78315870 has 16 divisors (see below), whose sum is σ = 187958160. Its totient is φ = 20884224.

The previous prime is 78315869. The next prime is 78315883. The reversal of 78315870 is 7851387.

It is a super-2 number, since 2×78315870² = 12266750987713800, 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 7 ways as a sum of consecutive naturals, for example, 1305235 + ... + 1305294.

It is an arithmetic number, because the mean of its divisors is an integer number (11747385).

Almost surely, 2^78315870 is an apocalyptic number.

78315870 is an abundant number, since it is smaller than the sum of its proper divisors (109642290).

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

78315870 is a wasteful number, since it uses less digits than its factorization.

78315870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2610539.

The product of its (nonzero) digits is 47040, while the sum is 39.

The square root of 78315870 is about 8849.6254158015. The cubic root of 78315870 is about 427.8418455168.

It can be divided in two parts, 783 and 15870, that added together give a triangular number (16653 = T₁₈₂).

The spelling of 78315870 in words is "seventy-eight million, three hundred fifteen thousand, eight hundred seventy".