72213131 has 2 divisors, whose sum is σ = 72213132. Its totient is φ = 72213130.

The previous prime is 72213107. The next prime is 72213143. The reversal of 72213131 is 13131227.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 72213131 - 2⁶ = 72213067 is a prime.

It is a super-2 number, since 2×72213131² = 10429472577646322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (72213151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36106565 + 36106566.

It is an arithmetic number, because the mean of its divisors is an integer number (36106566).

Almost surely, 2^72213131 is an apocalyptic number.

72213131 is a deficient number, since it is larger than the sum of its proper divisors (1).

72213131 is an equidigital number, since it uses as much as digits as its factorization.

72213131 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 252, while the sum is 20.

The square root of 72213131 is about 8497.8309585447. The cubic root of 72213131 is about 416.4268512969.

Adding to 72213131 its reverse (13131227), we get a palindrome (85344358).

The spelling of 72213131 in words is "seventy-two million, two hundred thirteen thousand, one hundred thirty-one".