90457921 has 2 divisors, whose sum is σ = 90457922. Its totient is φ = 90457920.

The previous prime is 90457889. The next prime is 90457957. The reversal of 90457921 is 12975409.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 90345025 + 112896 = 9505^2 + 336^2 .

It is a cyclic number.

It is not a de Polignac number, because 90457921 - 2⁵ = 90457889 is a prime.

It is not a weakly prime, because it can be changed into another prime (90457021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45228960 + 45228961.

It is an arithmetic number, because the mean of its divisors is an integer number (45228961).

Almost surely, 2^90457921 is an apocalyptic number.

It is an amenable number.

90457921 is a deficient number, since it is larger than the sum of its proper divisors (1).

90457921 is an equidigital number, since it uses as much as digits as its factorization.

90457921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 22680, while the sum is 37.

The square root of 90457921 is about 9510.9369149417. The cubic root of 90457921 is about 448.8992371478.

It can be divided in two parts, 90457 and 921, that added together give a triangular number (91378 = T₄₂₇).

The spelling of 90457921 in words is "ninety million, four hundred fifty-seven thousand, nine hundred twenty-one".