13366921 has 4 divisors (see below), whose sum is σ = 13798144. Its totient is φ = 12935700.

The previous prime is 13366919. The next prime is 13366949. The reversal of 13366921 is 12966331.

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 not a de Polignac number, because 13366921 - 2¹ = 13366919 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 431191 = 13366921 / (1 + 3 + 3 + 6 + 6 + 9 + 2 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13366961) 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, 215565 + ... + 215626.

It is an arithmetic number, because the mean of its divisors is an integer number (3449536).

Almost surely, 2^13366921 is an apocalyptic number.

It is an amenable number.

13366921 is a deficient number, since it is larger than the sum of its proper divisors (431223).

13366921 is an equidigital number, since it uses as much as digits as its factorization.

13366921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 431222.

The product of its digits is 5832, while the sum is 31.

The square root of 13366921 is about 3656.0800045951. The cubic root of 13366921 is about 237.3251662506.

The spelling of 13366921 in words is "thirteen million, three hundred sixty-six thousand, nine hundred twenty-one".