78139884 has 24 divisors (see below), whose sum is σ = 182750400. Its totient is φ = 25986064.

The previous prime is 78139883. The next prime is 78139903. The reversal of 78139884 is 48893187.

It is a super-2 number, since 2×78139884² = 12211682943066912, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78139883) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2034 + ... + 12665.

It is an arithmetic number, because the mean of its divisors is an integer number (7614600).

Almost surely, 2^78139884 is an apocalyptic number.

It is an amenable number.

78139884 is an abundant number, since it is smaller than the sum of its proper divisors (104610516).

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

78139884 is a wasteful number, since it uses less digits than its factorization.

78139884 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15149 (or 15147 counting only the distinct ones).

The product of its digits is 387072, while the sum is 48.

The square root of 78139884 is about 8839.6766909203. The cubic root of 78139884 is about 427.5211329794.

The spelling of 78139884 in words is "seventy-eight million, one hundred thirty-nine thousand, eight hundred eighty-four".