990121099 has 6 divisors (see below), whose sum is σ = 1088315060. Its totient is φ = 900109980.

The previous prime is 990121091. The next prime is 990121127.

990121099 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 990121099 - 2³ = 990121091 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (990121091) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4091289 + ... + 4091530.

Almost surely, 2^990121099 is an apocalyptic number.

990121099 is a deficient number, since it is larger than the sum of its proper divisors (98193961).

990121099 is a wasteful number, since it uses less digits than its factorization.

990121099 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8182841 (or 8182830 counting only the distinct ones).

The product of its (nonzero) digits is 13122, while the sum is 40.

The square root of 990121099 is about 31466.1897756942. The cubic root of 990121099 is about 996.6961294607.

The spelling of 990121099 in words is "nine hundred ninety million, one hundred twenty-one thousand, ninety-nine".