9900990121 has 8 divisors (see below), whose sum is σ = 10872612288. Its totient is φ = 8941290000.

The previous prime is 9900990109. The next prime is 9900990139. The reversal of 9900990121 is 1210990099.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 9900990121 - 2⁵ = 9900990089 is a prime.

It is a super-2 number, since 2×9900990121² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9900990181) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2978770 + ... + 2982091.

It is an arithmetic number, because the mean of its divisors is an integer number (1359076536).

Almost surely, 2^9900990121 is an apocalyptic number.

It is an amenable number.

9900990121 is a deficient number, since it is larger than the sum of its proper divisors (971622167).

9900990121 is a wasteful number, since it uses less digits than its factorization.

9900990121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5961023.

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

The square root of 9900990121 is about 99503.7191314978. The cubic root of 9900990121 is about 2147.3007496863.

The spelling of 9900990121 in words is "nine billion, nine hundred million, nine hundred ninety thousand, one hundred twenty-one".