11939809 has 16 divisors (see below), whose sum is σ = 14515200. Its totient is φ = 9593424.

The previous prime is 11939791. The next prime is 11939813. The reversal of 11939809 is 90893911.

It is a cyclic number.

It is not a de Polignac number, because 11939809 - 2⁵ = 11939777 is a prime.

It is not an unprimeable number, because it can be changed into a prime (11939849) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13812 + ... + 14650.

It is an arithmetic number, because the mean of its divisors is an integer number (907200).

Almost surely, 2^11939809 is an apocalyptic number.

11939809 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

11939809 is a deficient number, since it is larger than the sum of its proper divisors (2575391).

11939809 is a wasteful number, since it uses less digits than its factorization.

11939809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 972.

The product of its (nonzero) digits is 17496, while the sum is 40.

The square root of 11939809 is about 3455.4028708676. The cubic root of 11939809 is about 228.5594206303.

The spelling of 11939809 in words is "eleven million, nine hundred thirty-nine thousand, eight hundred nine".