90221807520 has 288 divisors, whose sum is σ = 331971795792. Its totient is φ = 22181216256.

The previous prime is 90221807453. The next prime is 90221807527. The reversal of 90221807520 is 2570812209.

It can be written as a sum of positive squares in 8 ways, for example, as 36299394576 + 53922412944 = 190524^2 + 232212^2 .

It is a tau number, because it is divible by the number of its divisors (288).

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

It is not an unprimeable number, because it can be changed into a prime (90221807527) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 18286974 + ... + 18291906.

Almost surely, 2^90221807520 is an apocalyptic number.

90221807520 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 90221807520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (165985897896).

90221807520 is an abundant number, since it is smaller than the sum of its proper divisors (241749988272).

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

90221807520 is a wasteful number, since it uses less digits than its factorization.

90221807520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5944 (or 5933 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The spelling of 90221807520 in words is "ninety billion, two hundred twenty-one million, eight hundred seven thousand, five hundred twenty".