11991953 has 4 divisors (see below), whose sum is σ = 12697380. Its totient is φ = 11286528.

The previous prime is 11991943. The next prime is 11991977. The reversal of 11991953 is 35919911.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3564544 + 8427409 = 1888^2 + 2903^2 .

It is a cyclic number.

It is not a de Polignac number, because 11991953 - 2⁴ = 11991937 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (11991913) 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, 352688 + ... + 352721.

It is an arithmetic number, because the mean of its divisors is an integer number (3174345).

Almost surely, 2^11991953 is an apocalyptic number.

It is an amenable number.

11991953 is a deficient number, since it is larger than the sum of its proper divisors (705427).

11991953 is an equidigital number, since it uses as much as digits as its factorization.

11991953 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 705426.

The product of its digits is 10935, while the sum is 38.

The square root of 11991953 is about 3462.9399359504. The cubic root of 11991953 is about 228.8916619812.

The spelling of 11991953 in words is "eleven million, nine hundred ninety-one thousand, nine hundred fifty-three".