90121664598 has 64 divisors (see below), whose sum is σ = 210475418112. Its totient is φ = 25191429120.

The previous prime is 90121664587. The next prime is 90121664599. The reversal of 90121664598 is 89546612109.

It is a self number, because there is not a number n which added to its sum of digits gives 90121664598.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90121664599) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 728433 + ... + 843123.

It is an arithmetic number, because the mean of its divisors is an integer number (3288678408).

Almost surely, 2^90121664598 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 90121664598, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (105237709056).

90121664598 is an abundant number, since it is smaller than the sum of its proper divisors (120353753514).

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

90121664598 is a wasteful number, since it uses less digits than its factorization.

90121664598 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115109.

The product of its (nonzero) digits is 933120, while the sum is 51.

The spelling of 90121664598 in words is "ninety billion, one hundred twenty-one million, six hundred sixty-four thousand, five hundred ninety-eight".