90811999 has 2 divisors, whose sum is σ = 90812000. Its totient is φ = 90811998.

The previous prime is 90811997. The next prime is 90812003. The reversal of 90811999 is 99911809.

It is a weak prime.

It is an emirp because it is prime and its reverse (99911809) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 90811999 - 2¹ = 90811997 is a prime.

Together with 90811997, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90811997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45405999 + 45406000.

It is an arithmetic number, because the mean of its divisors is an integer number (45406000).

Almost surely, 2^90811999 is an apocalyptic number.

90811999 is a deficient number, since it is larger than the sum of its proper divisors (1).

90811999 is an equidigital number, since it uses as much as digits as its factorization.

90811999 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 52488, while the sum is 46.

The square root of 90811999 is about 9529.5329896066. The cubic root of 90811999 is about 449.4841809773.

The spelling of 90811999 in words is "ninety million, eight hundred eleven thousand, nine hundred ninety-nine".