72557971 has 4 divisors (see below), whose sum is σ = 75060000. Its totient is φ = 70055944.

The previous prime is 72557959. The next prime is 72557977. The reversal of 72557971 is 17975527.

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

It is a cyclic number.

It is not a de Polignac number, because 72557971 - 2¹³ = 72549779 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72557977) 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, 1250971 + ... + 1251028.

It is an arithmetic number, because the mean of its divisors is an integer number (18765000).

Almost surely, 2^72557971 is an apocalyptic number.

72557971 is a deficient number, since it is larger than the sum of its proper divisors (2502029).

72557971 is a wasteful number, since it uses less digits than its factorization.

72557971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2502028.

The product of its digits is 154350, while the sum is 43.

The square root of 72557971 is about 8518.0966770752. The cubic root of 72557971 is about 417.0886545764.

The spelling of 72557971 in words is "seventy-two million, five hundred fifty-seven thousand, nine hundred seventy-one".