90087997 has 2 divisors, whose sum is σ = 90087998. Its totient is φ = 90087996.

The previous prime is 90087989. The next prime is 90088021. The reversal of 90087997 is 79978009.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 82101721 + 7986276 = 9061^2 + 2826^2 .

It is a cyclic number.

It is not a de Polignac number, because 90087997 - 2³ = 90087989 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 90087997.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90087197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45043998 + 45043999.

It is an arithmetic number, because the mean of its divisors is an integer number (45043999).

Almost surely, 2^90087997 is an apocalyptic number.

It is an amenable number.

90087997 is a deficient number, since it is larger than the sum of its proper divisors (1).

90087997 is an equidigital number, since it uses as much as digits as its factorization.

90087997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 285768, while the sum is 49.

The square root of 90087997 is about 9491.4696965222. The cubic root of 90087997 is about 448.2864826997.

The spelling of 90087997 in words is "ninety million, eighty-seven thousand, nine hundred ninety-seven".