78617172 has 24 divisors (see below), whose sum is σ = 187915392. Its totient is φ = 25566400.

The previous prime is 78617141. The next prime is 78617183. The reversal of 78617172 is 27171687.

It is a self number, because there is not a number n which added to its sum of digits gives 78617172.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 79404 + ... + 80387.

It is an arithmetic number, because the mean of its divisors is an integer number (7829808).

Almost surely, 2^78617172 is an apocalyptic number.

It is an amenable number.

78617172 is an abundant number, since it is smaller than the sum of its proper divisors (109298220).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78617172 is a wasteful number, since it uses less digits than its factorization.

78617172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159839 (or 159837 counting only the distinct ones).

The product of its digits is 32928, while the sum is 39.

The square root of 78617172 is about 8866.6325061999. The cubic root of 78617172 is about 428.3898172100.

The spelling of 78617172 in words is "seventy-eight million, six hundred seventeen thousand, one hundred seventy-two".