72557977 has 2 divisors, whose sum is σ = 72557978. Its totient is φ = 72557976.

The previous prime is 72557959. The next prime is 72557981. The reversal of 72557977 is 77975527.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 72522256 + 35721 = 8516^2 + 189^2 .

It is a cyclic number.

It is not a de Polignac number, because 72557977 - 2¹⁵ = 72525209 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 72557977.

It is not a weakly prime, because it can be changed into another prime (72557917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36278988 + 36278989.

It is an arithmetic number, because the mean of its divisors is an integer number (36278989).

Almost surely, 2^72557977 is an apocalyptic number.

It is an amenable number.

72557977 is a deficient number, since it is larger than the sum of its proper divisors (1).

72557977 is an equidigital number, since it uses as much as digits as its factorization.

72557977 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1080450, while the sum is 49.

The square root of 72557977 is about 8518.0970292666. The cubic root of 72557977 is about 417.0886660731.

The spelling of 72557977 in words is "seventy-two million, five hundred fifty-seven thousand, nine hundred seventy-seven".