11638681 has 4 divisors (see below), whose sum is σ = 11909392. Its totient is φ = 11367972.

The previous prime is 11638673. The next prime is 11638687. The reversal of 11638681 is 18683611.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 11638681 - 2³ = 11638673 is a prime.

It is a super-2 number, since 2×11638681² = 270917790839522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11638687) 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 3 ways as a sum of consecutive naturals, for example, 135291 + ... + 135376.

It is an arithmetic number, because the mean of its divisors is an integer number (2977348).

Almost surely, 2^11638681 is an apocalyptic number.

It is an amenable number.

11638681 is a deficient number, since it is larger than the sum of its proper divisors (270711).

11638681 is an equidigital number, since it uses as much as digits as its factorization.

11638681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 270710.

The product of its digits is 6912, while the sum is 34.

The square root of 11638681 is about 3411.5511134966. The cubic root of 11638681 is about 226.6215757577.

The spelling of 11638681 in words is "eleven million, six hundred thirty-eight thousand, six hundred eighty-one".