11981637 has 6 divisors (see below), whose sum is σ = 17306822. Its totient is φ = 7987752.

The previous prime is 11981623. The next prime is 11981639. The reversal of 11981637 is 73618911.

11981637 is a `hidden beast` number, since 1 + 19 + 8 + 1 + 637 = 666.

It can be written as a sum of positive squares in only one way, i.e., 10556001 + 1425636 = 3249^2 + 1194^2 .

It is not a de Polignac number, because 11981637 - 2¹⁰ = 11980613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11981639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 665638 + ... + 665655.

Almost surely, 2^11981637 is an apocalyptic number.

It is an amenable number.

11981637 is a deficient number, since it is larger than the sum of its proper divisors (5325185).

11981637 is a wasteful number, since it uses less digits than its factorization.

11981637 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1331299 (or 1331296 counting only the distinct ones).

The product of its digits is 9072, while the sum is 36.

The square root of 11981637 is about 3461.4501296422. The cubic root of 11981637 is about 228.8260089612.

The spelling of 11981637 in words is "eleven million, nine hundred eighty-one thousand, six hundred thirty-seven".