78198172 has 12 divisors (see below), whose sum is σ = 147373576. Its totient is φ = 36091440.

The previous prime is 78198163. The next prime is 78198191. The reversal of 78198172 is 27189187.

It is a happy number.

It is a super-2 number, since 2×78198172² = 12229908208283168, which contains 22 as substring.

It is a congruent number.

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 in 3 ways as a sum of consecutive naturals, for example, 751854 + ... + 751957.

Almost surely, 2^78198172 is an apocalyptic number.

It is an amenable number.

78198172 is a deficient number, since it is larger than the sum of its proper divisors (69175404).

78198172 is a wasteful number, since it uses less digits than its factorization.

78198172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1503828 (or 1503826 counting only the distinct ones).

The product of its digits is 56448, while the sum is 43.

The square root of 78198172 is about 8842.9730294737. The cubic root of 78198172 is about 427.6274088740.

The spelling of 78198172 in words is "seventy-eight million, one hundred ninety-eight thousand, one hundred seventy-two".