72656989 has 2 divisors, whose sum is σ = 72656990. Its totient is φ = 72656988.

The previous prime is 72656869. The next prime is 72656993. The reversal of 72656989 is 98965627.

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., 52925625 + 19731364 = 7275^2 + 4442^2 .

It is a cyclic number.

It is not a de Polignac number, because 72656989 - 2¹¹ = 72654941 is a prime.

It is a super-2 number, since 2×72656989² = 10558076101092242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72656999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36328494 + 36328495.

It is an arithmetic number, because the mean of its divisors is an integer number (36328495).

Almost surely, 2^72656989 is an apocalyptic number.

It is an amenable number.

72656989 is a deficient number, since it is larger than the sum of its proper divisors (1).

72656989 is an equidigital number, since it uses as much as digits as its factorization.

72656989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1632960, while the sum is 52.

The square root of 72656989 is about 8523.9069093931. The cubic root of 72656989 is about 417.2782983944.

The spelling of 72656989 in words is "seventy-two million, six hundred fifty-six thousand, nine hundred eighty-nine".