11687681 has 4 divisors (see below), whose sum is σ = 11862192. Its totient is φ = 11513172.

The previous prime is 11687677. The next prime is 11687693. The reversal of 11687681 is 18678611.

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 11687681 - 2² = 11687677 is a prime.

It is a super-2 number, since 2×11687681² = 273203774315522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11687281) 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, 87155 + ... + 87288.

It is an arithmetic number, because the mean of its divisors is an integer number (2965548).

Almost surely, 2^11687681 is an apocalyptic number.

It is an amenable number.

11687681 is a deficient number, since it is larger than the sum of its proper divisors (174511).

11687681 is an equidigital number, since it uses as much as digits as its factorization.

11687681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174510.

The product of its digits is 16128, while the sum is 38.

The square root of 11687681 is about 3418.7250547536. The cubic root of 11687681 is about 226.9391635765.

The spelling of 11687681 in words is "eleven million, six hundred eighty-seven thousand, six hundred eighty-one".