90539021 has 2 divisors, whose sum is σ = 90539022. Its totient is φ = 90539020.

The previous prime is 90538979. The next prime is 90539023. The reversal of 90539021 is 12093509.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 88548100 + 1990921 = 9410^2 + 1411^2 .

It is an emirp because it is prime and its reverse (12093509) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 90539021 - 2²⁶ = 23430157 is a prime.

Together with 90539023, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90539023) 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, 45269510 + 45269511.

It is an arithmetic number, because the mean of its divisors is an integer number (45269511).

Almost surely, 2^90539021 is an apocalyptic number.

It is an amenable number.

90539021 is a deficient number, since it is larger than the sum of its proper divisors (1).

90539021 is an equidigital number, since it uses as much as digits as its factorization.

90539021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2430, while the sum is 29.

The square root of 90539021 is about 9515.1994724231. The cubic root of 90539021 is about 449.0333505319.

The spelling of 90539021 in words is "ninety million, five hundred thirty-nine thousand, twenty-one".