72165979 has 4 divisors (see below), whose sum is σ = 72426784. Its totient is φ = 71905176.

The previous prime is 72165953. The next prime is 72165991. The reversal of 72165979 is 97956127.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97956127 = 337 ⋅290671.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72165979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72165679) by changing a digit.

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, 129987 + ... + 130540.

It is an arithmetic number, because the mean of its divisors is an integer number (18106696).

Almost surely, 2^72165979 is an apocalyptic number.

72165979 is a deficient number, since it is larger than the sum of its proper divisors (260805).

72165979 is a wasteful number, since it uses less digits than its factorization.

72165979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 260804.

The product of its digits is 238140, while the sum is 46.

The square root of 72165979 is about 8495.0561504913. The cubic root of 72165979 is about 416.3361954201.

The spelling of 72165979 in words is "seventy-two million, one hundred sixty-five thousand, nine hundred seventy-nine".