90997811 has 2 divisors, whose sum is σ = 90997812. Its totient is φ = 90997810.

The previous prime is 90997793. The next prime is 90997817. The reversal of 90997811 is 11879909.

It is a strong prime.

It is an emirp because it is prime and its reverse (11879909) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-90997811 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (90997817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45498905 + 45498906.

It is an arithmetic number, because the mean of its divisors is an integer number (45498906).

Almost surely, 2^90997811 is an apocalyptic number.

90997811 is a deficient number, since it is larger than the sum of its proper divisors (1).

90997811 is an equidigital number, since it uses as much as digits as its factorization.

90997811 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40824, while the sum is 44.

The square root of 90997811 is about 9539.2772787041. The cubic root of 90997811 is about 449.7905379075.

The spelling of 90997811 in words is "ninety million, nine hundred ninety-seven thousand, eight hundred eleven".