78639513 has 8 divisors (see below), whose sum is σ = 105496608. Its totient is φ = 52104384.

The previous prime is 78639511. The next prime is 78639527. The reversal of 78639513 is 31593687.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 78639513 - 2¹ = 78639511 is a prime.

It is not an unprimeable number, because it can be changed into a prime (78639511) 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, 79920 + ... + 80897.

It is an arithmetic number, because the mean of its divisors is an integer number (13187076).

Almost surely, 2^78639513 is an apocalyptic number.

It is an amenable number.

78639513 is a deficient number, since it is larger than the sum of its proper divisors (26857095).

78639513 is a wasteful number, since it uses less digits than its factorization.

78639513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160983.

The product of its digits is 136080, while the sum is 42.

The square root of 78639513 is about 8867.8922523901. The cubic root of 78639513 is about 428.4303925289.

The spelling of 78639513 in words is "seventy-eight million, six hundred thirty-nine thousand, five hundred thirteen".