11591921 has 6 divisors (see below), whose sum is σ = 12741666. Its totient is φ = 10538000.

The previous prime is 11591911. The next prime is 11591947. The reversal of 11591921 is 12919511.

11591921 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 10817521 + 774400 = 3289^2 + 880^2 .

It is not a de Polignac number, because 11591921 - 2⁶ = 11591857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11591911) 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 5 ways as a sum of consecutive naturals, for example, 47780 + ... + 48021.

It is an arithmetic number, because the mean of its divisors is an integer number (2123611).

Almost surely, 2^11591921 is an apocalyptic number.

11591921 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

11591921 is a deficient number, since it is larger than the sum of its proper divisors (1149745).

11591921 is an equidigital number, since it uses as much as digits as its factorization.

11591921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95823 (or 95812 counting only the distinct ones).

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

The square root of 11591921 is about 3404.6910285663. The cubic root of 11591921 is about 226.3176739655.

The spelling of 11591921 in words is "eleven million, five hundred ninety-one thousand, nine hundred twenty-one".