11915921 has 4 divisors (see below), whose sum is σ = 11976000. Its totient is φ = 11855844.

The previous prime is 11915903. The next prime is 11915927. The reversal of 11915921 is 12951911.

11915921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 a de Polignac number, because none of the positive numbers 2^k-11915921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11915927) 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, 29741 + ... + 30138.

It is an arithmetic number, because the mean of its divisors is an integer number (2994000).

Almost surely, 2^11915921 is an apocalyptic number.

It is an amenable number.

11915921 is a deficient number, since it is larger than the sum of its proper divisors (60079).

11915921 is an equidigital number, since it uses as much as digits as its factorization.

11915921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60078.

The product of its digits is 810, while the sum is 29.

The square root of 11915921 is about 3451.9445244673. The cubic root of 11915921 is about 228.4068924323.

The spelling of 11915921 in words is "eleven million, nine hundred fifteen thousand, nine hundred twenty-one".