78135912 has 24 divisors (see below), whose sum is σ = 211618290. Its totient is φ = 26045280.

The previous prime is 78135907. The next prime is 78135919. The reversal of 78135912 is 21953187.

It can be written as a sum of positive squares in only one way, i.e., 52794756 + 25341156 = 7266^2 + 5034^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-2 number, since 2×78135912² = 12210441488143488, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (78135919) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 542539 + ... + 542682.

Almost surely, 2^78135912 is an apocalyptic number.

78135912 is a gapful number since it is divisible by the number (72) formed by its first and last digit.

It is an amenable number.

78135912 is an abundant number, since it is smaller than the sum of its proper divisors (133482378).

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

78135912 is a wasteful number, since it uses less digits than its factorization.

78135912 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1085233 (or 1085226 counting only the distinct ones).

The product of its digits is 15120, while the sum is 36.

The square root of 78135912 is about 8839.4520192148. The cubic root of 78135912 is about 427.5138889506.

The spelling of 78135912 in words is "seventy-eight million, one hundred thirty-five thousand, nine hundred twelve".