90005998 has 4 divisors (see below), whose sum is σ = 135009000. Its totient is φ = 45002998.

The previous prime is 90005977. The next prime is 90005999. The reversal of 90005998 is 89950009.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 90005998.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90005999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 22501498 + ... + 22501501.

It is an arithmetic number, because the mean of its divisors is an integer number (33752250).

Almost surely, 2^90005998 is an apocalyptic number.

90005998 is a deficient number, since it is larger than the sum of its proper divisors (45003002).

90005998 is a wasteful number, since it uses less digits than its factorization.

90005998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45003001.

The product of its (nonzero) digits is 29160, while the sum is 40.

The square root of 90005998 is about 9487.1490975951. The cubic root of 90005998 is about 448.1504297922.

The spelling of 90005998 in words is "ninety million, five thousand, nine hundred ninety-eight".