72220531 has 2 divisors, whose sum is σ = 72220532. Its totient is φ = 72220530.

The previous prime is 72220517. The next prime is 72220537. The reversal of 72220531 is 13502227.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 72220531 - 2⁹ = 72220019 is a prime.

It is a super-2 number, since 2×72220531² = 10431610195843922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (72220537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36110265 + 36110266.

It is an arithmetic number, because the mean of its divisors is an integer number (36110266).

Almost surely, 2^72220531 is an apocalyptic number.

72220531 is a deficient number, since it is larger than the sum of its proper divisors (1).

72220531 is an equidigital number, since it uses as much as digits as its factorization.

72220531 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 840, while the sum is 22.

The square root of 72220531 is about 8498.2663526157. The cubic root of 72220531 is about 416.4410751802.

Adding to 72220531 its reverse (13502227), we get a palindrome (85722758).

The spelling of 72220531 in words is "seventy-two million, two hundred twenty thousand, five hundred thirty-one".