90187920 has 60 divisors (see below), whose sum is σ = 302883516. Its totient is φ = 24049920.

The previous prime is 90187919. The next prime is 90187961. The reversal of 90187920 is 2978109.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 13660416 + 76527504 = 3696^2 + 8748^2 .

It is a tau number, because it is divible by the number of its divisors (60).

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 61911 + ... + 63350.

Almost surely, 2^90187920 is an apocalyptic number.

90187920 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

90187920 is an abundant number, since it is smaller than the sum of its proper divisors (212695596).

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

90187920 is a wasteful number, since it uses less digits than its factorization.

90187920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125280 (or 125271 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 90187920 is about 9496.7320695069. The cubic root of 90187920 is about 448.4521635911.

The spelling of 90187920 in words is "ninety million, one hundred eighty-seven thousand, nine hundred twenty".