11981633 has 4 divisors (see below), whose sum is σ = 12043908. Its totient is φ = 11919360.

The previous prime is 11981623. The next prime is 11981639. The reversal of 11981633 is 33618911.

11981633 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.

It can be written as a sum of positive squares in 2 ways, for example, as 1373584 + 10608049 = 1172^2 + 3257^2 .

It is a cyclic number.

It is not a de Polignac number, because 11981633 - 2¹⁰ = 11980609 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 11981633.

It is not an unprimeable number, because it can be changed into a prime (11981639) 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, 30848 + ... + 31233.

It is an arithmetic number, because the mean of its divisors is an integer number (3010977).

Almost surely, 2^11981633 is an apocalyptic number.

It is an amenable number.

11981633 is a deficient number, since it is larger than the sum of its proper divisors (62275).

11981633 is an equidigital number, since it uses as much as digits as its factorization.

11981633 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62274.

The product of its digits is 3888, while the sum is 32.

The square root of 11981633 is about 3461.4495518496. The cubic root of 11981633 is about 228.8259834971.

The spelling of 11981633 in words is "eleven million, nine hundred eighty-one thousand, six hundred thirty-three".