90530021 has 2 divisors, whose sum is σ = 90530022. Its totient is φ = 90530020.

The previous prime is 90529993. The next prime is 90530023. The reversal of 90530021 is 12003509.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 70324996 + 20205025 = 8386^2 + 4495^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-90530021 is a prime.

It is a Sophie Germain prime.

Together with 90530023, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 90529975 and 90530002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90530023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45265010 + 45265011.

It is an arithmetic number, because the mean of its divisors is an integer number (45265011).

Almost surely, 2^90530021 is an apocalyptic number.

It is an amenable number.

90530021 is a deficient number, since it is larger than the sum of its proper divisors (1).

90530021 is an equidigital number, since it uses as much as digits as its factorization.

90530021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 270, while the sum is 20.

The square root of 90530021 is about 9514.7265331170. The cubic root of 90530021 is about 449.0184713707.

The spelling of 90530021 in words is "ninety million, five hundred thirty thousand, twenty-one".