13199921 has 4 divisors (see below), whose sum is σ = 15085632. Its totient is φ = 11314212.

The previous prime is 13199917. The next prime is 13199929. The reversal of 13199921 is 12999131.

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 not a de Polignac number, because 13199921 - 2² = 13199917 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 (13199929) 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, 942845 + ... + 942858.

It is an arithmetic number, because the mean of its divisors is an integer number (3771408).

Almost surely, 2^13199921 is an apocalyptic number.

It is an amenable number.

13199921 is a deficient number, since it is larger than the sum of its proper divisors (1885711).

13199921 is an equidigital number, since it uses as much as digits as its factorization.

13199921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1885710.

The product of its digits is 4374, while the sum is 35.

The square root of 13199921 is about 3633.1695528835. The cubic root of 13199921 is about 236.3326786199.

The spelling of 13199921 in words is "thirteen million, one hundred ninety-nine thousand, nine hundred twenty-one".