13679921 has 4 divisors (see below), whose sum is σ = 13904244. Its totient is φ = 13455600.

The previous prime is 13679903. The next prime is 13679927. The reversal of 13679921 is 12997631.

It is a happy number.

13679921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 255025 + 13424896 = 505^2 + 3664^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13679921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13679927) 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, 112070 + ... + 112191.

It is an arithmetic number, because the mean of its divisors is an integer number (3476061).

Almost surely, 2^13679921 is an apocalyptic number.

It is an amenable number.

13679921 is a deficient number, since it is larger than the sum of its proper divisors (224323).

13679921 is an equidigital number, since it uses as much as digits as its factorization.

13679921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224322.

The product of its digits is 20412, while the sum is 38.

The square root of 13679921 is about 3698.6377221891. The cubic root of 13679921 is about 239.1632959066.

The spelling of 13679921 in words is "thirteen million, six hundred seventy-nine thousand, nine hundred twenty-one".