78999980 has 24 divisors (see below), whose sum is σ = 166653312. Its totient is φ = 31456512.

The previous prime is 78999979. The next prime is 79000007. The reversal of 78999980 is 8999987.

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, 4397 + ... + 13316.

It is an arithmetic number, because the mean of its divisors is an integer number (6943888).

Almost surely, 2^78999980 is an apocalyptic number.

It is an amenable number.

78999980 is an abundant number, since it is smaller than the sum of its proper divisors (87653332).

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

78999980 is a wasteful number, since it uses less digits than its factorization.

78999980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17945 (or 17943 counting only the distinct ones).

The product of its (nonzero) digits is 2939328, while the sum is 59.

The square root of 78999980 is about 8888.1932922276. The cubic root of 78999980 is about 429.0840064930.

The spelling of 78999980 in words is "seventy-eight million, nine hundred ninety-nine thousand, nine hundred eighty".