90021213 has 20 divisors (see below), whose sum is σ = 134869020. Its totient is φ = 59838912.

The previous prime is 90021209. The next prime is 90021223. The reversal of 90021213 is 31212009.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 40487769 + 49533444 = 6363^2 + 7038^2 .

It is not a de Polignac number, because 90021213 - 2² = 90021209 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90021203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 30081 + ... + 32937.

It is an arithmetic number, because the mean of its divisors is an integer number (6743451).

Almost surely, 2^90021213 is an apocalyptic number.

It is an amenable number.

90021213 is a deficient number, since it is larger than the sum of its proper divisors (44847807).

90021213 is a wasteful number, since it uses less digits than its factorization.

90021213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3258 (or 3249 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

The square root of 90021213 is about 9487.9509379001. The cubic root of 90021213 is about 448.1756807931.

The spelling of 90021213 in words is "ninety million, twenty-one thousand, two hundred thirteen".