99566591 has 2 divisors, whose sum is σ = 99566592. Its totient is φ = 99566590.

The previous prime is 99566561. The next prime is 99566639. The reversal of 99566591 is 19566599.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 99566591 - 2⁶ = 99566527 is a prime.

It is a super-2 number, since 2×99566591² = 19827012086722562, which contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99566561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49783295 + 49783296.

It is an arithmetic number, because the mean of its divisors is an integer number (49783296).

Almost surely, 2^99566591 is an apocalyptic number.

99566591 is a deficient number, since it is larger than the sum of its proper divisors (1).

99566591 is an equidigital number, since it uses as much as digits as its factorization.

99566591 is an evil number, because the sum of its binary digits is even.

The product of its digits is 656100, while the sum is 50.

The square root of 99566591 is about 9978.3060185585. The cubic root of 99566591 is about 463.4873434618.

The spelling of 99566591 in words is "ninety-nine million, five hundred sixty-six thousand, five hundred ninety-one".