90639760 has 20 divisors (see below), whose sum is σ = 210737628. Its totient is φ = 36255872.

The previous prime is 90639749. The next prime is 90639763. The reversal of 90639760 is 6793609.

It can be written as a sum of positive squares in 2 ways, for example, as 39488656 + 51151104 = 6284^2 + 7152^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is not an unprimeable number, because it can be changed into a prime (90639763) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 566419 + ... + 566578.

Almost surely, 2^90639760 is an apocalyptic number.

It is an amenable number.

90639760 is an abundant number, since it is smaller than the sum of its proper divisors (120097868).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

90639760 is a wasteful number, since it uses less digits than its factorization.

90639760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1133010 (or 1133004 counting only the distinct ones).

The product of its (nonzero) digits is 61236, while the sum is 40.

The square root of 90639760 is about 9520.4915839467. The cubic root of 90639760 is about 449.1998290420.

The spelling of 90639760 in words is "ninety million, six hundred thirty-nine thousand, seven hundred sixty".