78136929 has 12 divisors (see below), whose sum is σ = 121546516. Its totient is φ = 48084192.

The previous prime is 78136921. The next prime is 78136931. The reversal of 78136929 is 92963187.

It can be written as a sum of positive squares in 2 ways, for example, as 8381025 + 69755904 = 2895^2 + 8352^2 .

It is not a de Polignac number, because 78136929 - 2³ = 78136921 is a prime.

It is a super-2 number, since 2×78136929² = 12210759347102082, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78136921) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 333802 + ... + 334035.

Almost surely, 2^78136929 is an apocalyptic number.

It is an amenable number.

78136929 is a deficient number, since it is larger than the sum of its proper divisors (43409587).

78136929 is a wasteful number, since it uses less digits than its factorization.

78136929 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 667856 (or 667853 counting only the distinct ones).

The product of its digits is 163296, while the sum is 45.

The square root of 78136929 is about 8839.5095452180. The cubic root of 78136929 is about 427.5157437518.

The spelling of 78136929 in words is "seventy-eight million, one hundred thirty-six thousand, nine hundred twenty-nine".