90090090 has 32 divisors (see below), whose sum is σ = 240240960. Its totient is φ = 24023952.

The previous prime is 90090053. The next prime is 90090097. The reversal of 90090090 is 9009009.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

90090090 is a modest number, since divided by 90090 gives 90 as remainder.

It is not an unprimeable number, because it can be changed into a prime (90090097) 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, 166564 + ... + 167103.

It is an arithmetic number, because the mean of its divisors is an integer number (7507530).

Almost surely, 2^90090090 is an apocalyptic number.

90090090 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

90090090 is an abundant number, since it is smaller than the sum of its proper divisors (150150870).

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

90090090 is a wasteful number, since it uses less digits than its factorization.

90090090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333683 (or 333677 counting only the distinct ones).

The product of its (nonzero) digits is 729, while the sum is 27.

The square root of 90090090 is about 9491.5799527792. The cubic root of 90090090 is about 448.2899543288.

Adding to 90090090 its reverse (9009009), we get a palindrome (99099099).

The spelling of 90090090 in words is "ninety million, ninety thousand, ninety".