78447172 has 12 divisors (see below), whose sum is σ = 137604096. Its totient is φ = 39131720.

The previous prime is 78447137. The next prime is 78447221. The reversal of 78447172 is 27174487.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21028 + ... + 24475.

It is an arithmetic number, because the mean of its divisors is an integer number (11467008).

Almost surely, 2^78447172 is an apocalyptic number.

It is an amenable number.

78447172 is a deficient number, since it is larger than the sum of its proper divisors (59156924).

78447172 is a wasteful number, since it uses less digits than its factorization.

78447172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45938 (or 45936 counting only the distinct ones).

The product of its digits is 87808, while the sum is 40.

The square root of 78447172 is about 8857.0408150804. The cubic root of 78447172 is about 428.0808142155.

The spelling of 78447172 in words is "seventy-eight million, four hundred forty-seven thousand, one hundred seventy-two".