13664921 has 8 divisors (see below), whose sum is σ = 14563584. Its totient is φ = 12791680.

The previous prime is 13664909. The next prime is 13664929. The reversal of 13664921 is 12946631.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-13664921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13664929) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5240 + ... + 7401.

It is an arithmetic number, because the mean of its divisors is an integer number (1820448).

Almost surely, 2^13664921 is an apocalyptic number.

It is an amenable number.

13664921 is a deficient number, since it is larger than the sum of its proper divisors (898663).

13664921 is a wasteful number, since it uses less digits than its factorization.

13664921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12711.

The product of its digits is 7776, while the sum is 32.

The square root of 13664921 is about 3696.6093924027. The cubic root of 13664921 is about 239.0758499472.

The spelling of 13664921 in words is "thirteen million, six hundred sixty-four thousand, nine hundred twenty-one".