72136979 has 4 divisors (see below), whose sum is σ = 72155160. Its totient is φ = 72118800.

The previous prime is 72136973. The next prime is 72136991. The reversal of 72136979 is 97963127.

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: 97963127 = 4973 ⋅19699.

It is a cyclic number.

It is not a de Polignac number, because 72136979 - 2⁸ = 72136723 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72136973) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 314 + ... + 12015.

It is an arithmetic number, because the mean of its divisors is an integer number (18038790).

Almost surely, 2^72136979 is an apocalyptic number.

72136979 is a deficient number, since it is larger than the sum of its proper divisors (18181).

72136979 is a wasteful number, since it uses less digits than its factorization.

72136979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18180.

The product of its digits is 142884, while the sum is 44.

The square root of 72136979 is about 8493.3491038577. The cubic root of 72136979 is about 416.2804195200.

The spelling of 72136979 in words is "seventy-two million, one hundred thirty-six thousand, nine hundred seventy-nine".