90707021 has 8 divisors (see below), whose sum is σ = 91728504. Its totient is φ = 89689600.

The previous prime is 90706999. The next prime is 90707027. The reversal of 90707021 is 12070709.

It can be written as a sum of positive squares in 4 ways, for example, as 30085225 + 60621796 = 5485^2 + 7786^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 90707021 - 2¹⁸ = 90444877 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90707027) 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 in 7 ways as a sum of consecutive naturals, for example, 69071 + ... + 70371.

It is an arithmetic number, because the mean of its divisors is an integer number (11466063).

Almost surely, 2^90707021 is an apocalyptic number.

It is an amenable number.

90707021 is a deficient number, since it is larger than the sum of its proper divisors (1021483).

90707021 is a wasteful number, since it uses less digits than its factorization.

90707021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2031.

The product of its (nonzero) digits is 882, while the sum is 26.

The square root of 90707021 is about 9524.0233620041. The cubic root of 90707021 is about 449.3109140642.

The spelling of 90707021 in words is "ninety million, seven hundred seven thousand, twenty-one".