13989866921 has 4 divisors (see below), whose sum is σ = 14287523712. Its totient is φ = 13692210132.

The previous prime is 13989866911. The next prime is 13989866923. The reversal of 13989866921 is 12966898931.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13989866921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13989866923) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 148828325 + ... + 148828418.

It is an arithmetic number, because the mean of its divisors is an integer number (3571880928).

Almost surely, 2^13989866921 is an apocalyptic number.

It is an amenable number.

13989866921 is a deficient number, since it is larger than the sum of its proper divisors (297656791).

13989866921 is an equidigital number, since it uses as much as digits as its factorization.

13989866921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 297656790.

The product of its digits is 10077696, while the sum is 62.

The spelling of 13989866921 in words is "thirteen billion, nine hundred eighty-nine million, eight hundred sixty-six thousand, nine hundred twenty-one".