90088021 has 2 divisors, whose sum is σ = 90088022. Its totient is φ = 90088020.

The previous prime is 90087997. The next prime is 90088027. The reversal of 90088021 is 12088009.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 86285521 + 3802500 = 9289^2 + 1950^2 .

It is a cyclic number.

It is not a de Polignac number, because 90088021 - 2⁵ = 90087989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90088027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45044010 + 45044011.

It is an arithmetic number, because the mean of its divisors is an integer number (45044011).

Almost surely, 2^90088021 is an apocalyptic number.

It is an amenable number.

90088021 is a deficient number, since it is larger than the sum of its proper divisors (1).

90088021 is an equidigital number, since it uses as much as digits as its factorization.

90088021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 28.

The square root of 90088021 is about 9491.4709608153. The cubic root of 90088021 is about 448.2865225084.

The spelling of 90088021 in words is "ninety million, eighty-eight thousand, twenty-one".