13715921 has 4 divisors (see below), whose sum is σ = 13728612. Its totient is φ = 13703232.

The previous prime is 13715917. The next prime is 13715939. The reversal of 13715921 is 12951731.

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 7639696 + 6076225 = 2764^2 + 2465^2 .

It is a cyclic number.

It is not a de Polignac number, because 13715921 - 2² = 13715917 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 (13715621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4556 + ... + 6941.

It is an arithmetic number, because the mean of its divisors is an integer number (3432153).

Almost surely, 2^13715921 is an apocalyptic number.

It is an amenable number.

13715921 is a deficient number, since it is larger than the sum of its proper divisors (12691).

13715921 is a wasteful number, since it uses less digits than its factorization.

13715921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12690.

The product of its digits is 1890, while the sum is 29.

The square root of 13715921 is about 3703.5011813148. The cubic root of 13715921 is about 239.3729057210.

The spelling of 13715921 in words is "thirteen million, seven hundred fifteen thousand, nine hundred twenty-one".