9980123921 has 16 divisors (see below), whose sum is σ = 10679745024. Its totient is φ = 9293182464.

The previous prime is 9980123917. The next prime is 9980123927. The reversal of 9980123921 is 1293210899.

It is a happy number.

It is not a de Polignac number, because 9980123921 - 2² = 9980123917 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (9980123927) 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, 2601821 + ... + 2605653.

It is an arithmetic number, because the mean of its divisors is an integer number (667484064).

Almost surely, 2^9980123921 is an apocalyptic number.

It is an amenable number.

9980123921 is a deficient number, since it is larger than the sum of its proper divisors (699621103).

9980123921 is a wasteful number, since it uses less digits than its factorization.

9980123921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5440.

The product of its (nonzero) digits is 69984, while the sum is 44.

The square root of 9980123921 is about 99900.5701735481. The cubic root of 9980123921 is about 2153.0063528187.

The spelling of 9980123921 in words is "nine billion, nine hundred eighty million, one hundred twenty-three thousand, nine hundred twenty-one".