13911209 has 4 divisors (see below), whose sum is σ = 14981316. Its totient is φ = 12841104.

The previous prime is 13911203. The next prime is 13911229. The reversal of 13911209 is 90211931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90211931 = 41 ⋅2200291.

It can be written as a sum of positive squares in 2 ways, for example, as 2371600 + 11539609 = 1540^2 + 3397^2 .

It is a cyclic number.

It is not a de Polignac number, because 13911209 - 2⁴ = 13911193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13911203) 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, 535034 + ... + 535059.

It is an arithmetic number, because the mean of its divisors is an integer number (3745329).

Almost surely, 2^13911209 is an apocalyptic number.

It is an amenable number.

13911209 is a deficient number, since it is larger than the sum of its proper divisors (1070107).

13911209 is a wasteful number, since it uses less digits than its factorization.

13911209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1070106.

The product of its (nonzero) digits is 486, while the sum is 26.

The square root of 13911209 is about 3729.7733175087. The cubic root of 13911209 is about 240.5036241517.

The spelling of 13911209 in words is "thirteen million, nine hundred eleven thousand, two hundred nine".