90788318721 has 15 divisors (see below), whose sum is σ = 135626107441. Its totient is φ = 60523737948.

The previous prime is 90788318683. The next prime is 90788318743. The reversal of 90788318721 is 12781388709.

It is a happy number.

The square root of 90788318721 is 301311.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 90788318721 - 2³⁵ = 56428580353 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (90788318521) 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 14 ways as a sum of consecutive naturals, for example, 2695060 + ... + 2728538.

Almost surely, 2^90788318721 is an apocalyptic number.

90788318721 is the 301311-st square number.

90788318721 is the 150656-th centered octagonal number.

It is an amenable number.

90788318721 is a deficient number, since it is larger than the sum of its proper divisors (44837788720).

90788318721 is an frugal number, since it uses more digits than its factorization.

90788318721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66970 (or 33482 counting only the distinct ones).

The product of its (nonzero) digits is 1354752, while the sum is 54.

The spelling of 90788318721 in words is "ninety billion, seven hundred eighty-eight million, three hundred eighteen thousand, seven hundred twenty-one".