78172 has 6 divisors (see below), whose sum is σ = 136808. Its totient is φ = 39084.

The previous prime is 78167. The next prime is 78173. The reversal of 78172 is 27187.

It is a happy number.

It is a super-3 number, since 3×78172³ = 1433094815233344, which contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78173) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9768 + ... + 9775.

2⁷⁸¹⁷² is an apocalyptic number.

It is an amenable number.

78172 is a deficient number, since it is larger than the sum of its proper divisors (58636).

78172 is a wasteful number, since it uses less digits than its factorization.

78172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19547 (or 19545 counting only the distinct ones).

The product of its digits is 784, while the sum is 25.

The square root of 78172 is about 279.5925607022. The cubic root of 78172 is about 42.7579696278.

The spelling of 78172 in words is "seventy-eight thousand, one hundred seventy-two".