8999121021 has 48 divisors (see below), whose sum is σ = 13386941568. Its totient is φ = 5372674560.

The previous prime is 8999121017. The next prime is 8999121073. The reversal of 8999121021 is 1201219998.

8999121021 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 8999121021 - 2² = 8999121017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8999121091) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 8711121 + ... + 8712153.

It is an arithmetic number, because the mean of its divisors is an integer number (278894616).

Almost surely, 2^8999121021 is an apocalyptic number.

It is an amenable number.

8999121021 is a deficient number, since it is larger than the sum of its proper divisors (4387820547).

8999121021 is a wasteful number, since it uses less digits than its factorization.

8999121021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1394 (or 1383 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 42.

The square root of 8999121021 is about 94863.6970658428. The cubic root of 8999121021 is about 2080.0161041807.

The spelling of 8999121021 in words is "eight billion, nine hundred ninety-nine million, one hundred twenty-one thousand, twenty-one".