78139680 has 48 divisors (see below), whose sum is σ = 246141504. Its totient is φ = 20837120.

The previous prime is 78139673. The next prime is 78139693. The reversal of 78139680 is 8693187.

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-2 number, since 2×78139680² = 12211619181004800, which contains 22 as substring.

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, 80916 + ... + 81875.

It is an arithmetic number, because the mean of its divisors is an integer number (5127948).

Almost surely, 2^78139680 is an apocalyptic number.

It is an amenable number.

78139680 is an abundant number, since it is smaller than the sum of its proper divisors (168001824).

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

78139680 is a wasteful number, since it uses less digits than its factorization.

78139680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162809 (or 162801 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 42.

The square root of 78139680 is about 8839.6651520292. The cubic root of 78139680 is about 427.5207609356.

The spelling of 78139680 in words is "seventy-eight million, one hundred thirty-nine thousand, six hundred eighty".