90021888 has 224 divisors, whose sum is σ = 298825920. Its totient is φ = 26542080.

The previous prime is 90021881. The next prime is 90021907. The reversal of 90021888 is 88812009.

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 (90021881) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2433006 + ... + 2433042.

Almost surely, 2^90021888 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 90021888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (149412960).

90021888 is an abundant number, since it is smaller than the sum of its proper divisors (208804032).

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

90021888 is a wasteful number, since it uses less digits than its factorization.

90021888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83 (or 53 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 36.

The square root of 90021888 is about 9487.9865092653. The cubic root of 90021888 is about 448.1768009655.

It can be divided in two parts, 90021 and 888, that added together give a palindrome (90909).

The spelling of 90021888 in words is "ninety million, twenty-one thousand, eight hundred eighty-eight".