90997871 has 2 divisors, whose sum is σ = 90997872. Its totient is φ = 90997870.

The previous prime is 90997849. The next prime is 90997877. The reversal of 90997871 is 17879909.

It is a strong prime.

It is an emirp because it is prime and its reverse (17879909) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 90997871 - 2¹⁸ = 90735727 is a prime.

It is a super-2 number, since 2×90997871² = 16561225053065282, 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 (90997877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45498935 + 45498936.

It is an arithmetic number, because the mean of its divisors is an integer number (45498936).

Almost surely, 2^90997871 is an apocalyptic number.

90997871 is a deficient number, since it is larger than the sum of its proper divisors (1).

90997871 is an equidigital number, since it uses as much as digits as its factorization.

90997871 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 285768, while the sum is 50.

The square root of 90997871 is about 9539.2804235959. The cubic root of 90997871 is about 449.7906367649.

The spelling of 90997871 in words is "ninety million, nine hundred ninety-seven thousand, eight hundred seventy-one".