909561990 has 16 divisors (see below), whose sum is σ = 2182948848. Its totient is φ = 242549856.

The previous prime is 909561971. The next prime is 909562013. The reversal of 909561990 is 99165909.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15159337 + ... + 15159396.

It is an arithmetic number, because the mean of its divisors is an integer number (136434303).

Almost surely, 2^909561990 is an apocalyptic number.

909561990 is an abundant number, since it is smaller than the sum of its proper divisors (1273386858).

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

909561990 is a wasteful number, since it uses less digits than its factorization.

909561990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30318743.

The product of its (nonzero) digits is 196830, while the sum is 48.

The square root of 909561990 is about 30158.9454391230. The cubic root of 909561990 is about 968.8966055474.

The spelling of 909561990 in words is "nine hundred nine million, five hundred sixty-one thousand, nine hundred ninety".