72220537 has 2 divisors, whose sum is σ = 72220538. Its totient is φ = 72220536.

The previous prime is 72220531. The next prime is 72220549. The reversal of 72220537 is 73502227.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71554681 + 665856 = 8459^2 + 816^2 .

It is a cyclic number.

It is not a de Polignac number, because 72220537 - 2¹⁵ = 72187769 is a prime.

It is not a weakly prime, because it can be changed into another prime (72220531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36110268 + 36110269.

It is an arithmetic number, because the mean of its divisors is an integer number (36110269).

Almost surely, 2^72220537 is an apocalyptic number.

It is an amenable number.

72220537 is a deficient number, since it is larger than the sum of its proper divisors (1).

72220537 is an equidigital number, since it uses as much as digits as its factorization.

72220537 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5880, while the sum is 28.

The square root of 72220537 is about 8498.2667056289. The cubic root of 72220537 is about 416.4410867127.

The spelling of 72220537 in words is "seventy-two million, two hundred twenty thousand, five hundred thirty-seven".