78999964 has 6 divisors (see below), whose sum is σ = 138249944. Its totient is φ = 39499980.

The previous prime is 78999961. The next prime is 78999979. The reversal of 78999964 is 46999987.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78999961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9874992 + ... + 9874999.

Almost surely, 2^78999964 is an apocalyptic number.

It is an amenable number.

78999964 is a deficient number, since it is larger than the sum of its proper divisors (59249980).

78999964 is a wasteful number, since it uses less digits than its factorization.

78999964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19749995 (or 19749993 counting only the distinct ones).

The product of its digits is 8817984, while the sum is 61.

The square root of 78999964 is about 8888.1923921571. The cubic root of 78999964 is about 429.0839775253.

The spelling of 78999964 in words is "seventy-eight million, nine hundred ninety-nine thousand, nine hundred sixty-four".