78991532 has 6 divisors (see below), whose sum is σ = 138235188. Its totient is φ = 39495764.

The previous prime is 78991529. The next prime is 78991541. The reversal of 78991532 is 23519987.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9873938 + ... + 9873945.

It is an arithmetic number, because the mean of its divisors is an integer number (23039198).

Almost surely, 2^78991532 is an apocalyptic number.

It is an amenable number.

78991532 is a deficient number, since it is larger than the sum of its proper divisors (59243656).

78991532 is a wasteful number, since it uses less digits than its factorization.

78991532 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19747887 (or 19747885 counting only the distinct ones).

The product of its digits is 136080, while the sum is 44.

The square root of 78991532 is about 8887.7180423324. The cubic root of 78991532 is about 429.0687110001.

The spelling of 78991532 in words is "seventy-eight million, nine hundred ninety-one thousand, five hundred thirty-two".