72917139 has 4 divisors (see below), whose sum is σ = 97222856. Its totient is φ = 48611424.

The previous prime is 72917129. The next prime is 72917171. The reversal of 72917139 is 93171927.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 72917139 - 2⁴ = 72917123 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 72917097 and 72917106.

It is not an unprimeable number, because it can be changed into a prime (72917129) 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, 12152854 + ... + 12152859.

It is an arithmetic number, because the mean of its divisors is an integer number (24305714).

Almost surely, 2^72917139 is an apocalyptic number.

72917139 is a deficient number, since it is larger than the sum of its proper divisors (24305717).

72917139 is a wasteful number, since it uses less digits than its factorization.

72917139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24305716.

The product of its digits is 23814, while the sum is 39.

The square root of 72917139 is about 8539.1532952629. The cubic root of 72917139 is about 417.7757299871.

The spelling of 72917139 in words is "seventy-two million, nine hundred seventeen thousand, one hundred thirty-nine".