990900231 has 16 divisors (see below), whose sum is σ = 1344905856. Its totient is φ = 648840416.

The previous prime is 990900227. The next prime is 990900241. The reversal of 990900231 is 132009099.

It is a cyclic number.

It is not a de Polignac number, because 990900231 - 2² = 990900227 is a prime.

It is a super-2 number, since 2×990900231² = 1963766535591706722, which contains 22 as substring.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 990900192 and 990900201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (990900241) 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, 31576 + ... + 54578.

It is an arithmetic number, because the mean of its divisors is an integer number (84056616).

Almost surely, 2^990900231 is an apocalyptic number.

990900231 is a deficient number, since it is larger than the sum of its proper divisors (354005625).

990900231 is a wasteful number, since it uses less digits than its factorization.

990900231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23262.

The product of its (nonzero) digits is 4374, while the sum is 33.

The square root of 990900231 is about 31478.5678041426. The cubic root of 990900231 is about 996.9574962254.

The spelling of 990900231 in words is "nine hundred ninety million, nine hundred thousand, two hundred thirty-one".