90901681920 has 1728 divisors, whose sum is σ = 420876933120. Its totient is φ = 18101698560.

The previous prime is 90901681901. The next prime is 90901681961. The reversal of 90901681920 is 2918610909.

It is a tau number, because it is divible by the number of its divisors (1728).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 2932312305 + ... + 2932312335.

It is an arithmetic number, because the mean of its divisors is an integer number (243563040).

Almost surely, 2^90901681920 is an apocalyptic number.

90901681920 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 90901681920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (210438466560).

90901681920 is an abundant number, since it is smaller than the sum of its proper divisors (329975251200).

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

90901681920 is a wasteful number, since it uses less digits than its factorization.

90901681920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139 (or 88 counting only the distinct ones).

The product of its (nonzero) digits is 69984, while the sum is 45.

The spelling of 90901681920 in words is "ninety billion, nine hundred one million, six hundred eighty-one thousand, nine hundred twenty".