78508172 has 6 divisors (see below), whose sum is σ = 137389308. Its totient is φ = 39254084.

The previous prime is 78508141. The next prime is 78508187. The reversal of 78508172 is 27180587.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9813518 + ... + 9813525.

It is an arithmetic number, because the mean of its divisors is an integer number (22898218).

Almost surely, 2^78508172 is an apocalyptic number.

It is an amenable number.

78508172 is a deficient number, since it is larger than the sum of its proper divisors (58881136).

78508172 is a wasteful number, since it uses less digits than its factorization.

78508172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19627047 (or 19627045 counting only the distinct ones).

The product of its (nonzero) digits is 31360, while the sum is 38.

The square root of 78508172 is about 8860.4837339730. The cubic root of 78508172 is about 428.1917430674.

The spelling of 78508172 in words is "seventy-eight million, five hundred eight thousand, one hundred seventy-two".