90866591 has 2 divisors, whose sum is σ = 90866592. Its totient is φ = 90866590.

The previous prime is 90866579. The next prime is 90866609. The reversal of 90866591 is 19566809.

It is a weak prime.

It is an emirp because it is prime and its reverse (19566809) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 90866591 - 2⁶ = 90866527 is a prime.

It is a super-2 number, since 2×90866591² = 16513474719922562, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90866521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45433295 + 45433296.

It is an arithmetic number, because the mean of its divisors is an integer number (45433296).

Almost surely, 2^90866591 is an apocalyptic number.

90866591 is a deficient number, since it is larger than the sum of its proper divisors (1).

90866591 is an equidigital number, since it uses as much as digits as its factorization.

90866591 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 116640, while the sum is 44.

The square root of 90866591 is about 9532.3969178796. The cubic root of 90866591 is about 449.5742326784.

The spelling of 90866591 in words is "ninety million, eight hundred sixty-six thousand, five hundred ninety-one".