11506681 has 6 divisors (see below), whose sum is σ = 11758970. Its totient is φ = 11259696.

The previous prime is 11506679. The next prime is 11506699. The reversal of 11506681 is 18660511.

It can be written as a sum of positive squares in only one way, i.e., 11451456 + 55225 = 3384^2 + 235^2 .

It is not a de Polignac number, because 11506681 - 2¹ = 11506679 is a prime.

It is a super-2 number, since 2×11506681² = 264807415271522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11501681) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 396 + ... + 4813.

Almost surely, 2^11506681 is an apocalyptic number.

It is an amenable number.

11506681 is a deficient number, since it is larger than the sum of its proper divisors (252289).

11506681 is an frugal number, since it uses more digits than its factorization.

11506681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5303 (or 5256 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 11506681 is about 3392.1499082440. The cubic root of 11506681 is about 225.7615740683.

The spelling of 11506681 in words is "eleven million, five hundred six thousand, six hundred eighty-one".