97521989 has 2 divisors, whose sum is σ = 97521990. Its totient is φ = 97521988.

The previous prime is 97521971. The next prime is 97522021. The reversal of 97521989 is 98912579.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 83868964 + 13653025 = 9158^2 + 3695^2 .

It is a cyclic number.

It is not a de Polignac number, because 97521989 - 2²⁴ = 80744773 is a prime.

It is a super-2 number, since 2×97521989² = 19021076677032242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (97521089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48760994 + 48760995.

It is an arithmetic number, because the mean of its divisors is an integer number (48760995).

Almost surely, 2^97521989 is an apocalyptic number.

It is an amenable number.

97521989 is a deficient number, since it is larger than the sum of its proper divisors (1).

97521989 is an equidigital number, since it uses as much as digits as its factorization.

97521989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 408240, while the sum is 50.

The square root of 97521989 is about 9875.3222225910. The cubic root of 97521989 is about 460.2928019272.

The spelling of 97521989 in words is "ninety-seven million, five hundred twenty-one thousand, nine hundred eighty-nine".