11921565 has 16 divisors (see below), whose sum is σ = 19184256. Its totient is φ = 6321600.

The previous prime is 11921543. The next prime is 11921587. The reversal of 11921565 is 56512911.

11921565 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (11921543) and next prime (11921587).

It is not a de Polignac number, because 11921565 - 2⁶ = 11921501 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 520 + ... + 4910.

It is an arithmetic number, because the mean of its divisors is an integer number (1199016).

Almost surely, 2^11921565 is an apocalyptic number.

11921565 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

11921565 is a deficient number, since it is larger than the sum of its proper divisors (7262691).

11921565 is a wasteful number, since it uses less digits than its factorization.

11921565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4580.

The product of its digits is 2700, while the sum is 30.

The square root of 11921565 is about 3452.7619379274. The cubic root of 11921565 is about 228.4429485352.

The spelling of 11921565 in words is "eleven million, nine hundred twenty-one thousand, five hundred sixty-five".