11851681 has 2 divisors, whose sum is σ = 11851682. Its totient is φ = 11851680.

The previous prime is 11851673. The next prime is 11851753. The reversal of 11851681 is 18615811.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11621281 + 230400 = 3409^2 + 480^2 .

It is a cyclic number.

It is not a de Polignac number, because 11851681 - 2³ = 11851673 is a prime.

It is a super-2 number, since 2×11851681² = 280924685051522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (11851621) 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 as a sum of consecutive naturals, namely, 5925840 + 5925841.

It is an arithmetic number, because the mean of its divisors is an integer number (5925841).

Almost surely, 2^11851681 is an apocalyptic number.

It is an amenable number.

11851681 is a deficient number, since it is larger than the sum of its proper divisors (1).

11851681 is an equidigital number, since it uses as much as digits as its factorization.

11851681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1920, while the sum is 31.

The square root of 11851681 is about 3442.6270492169. The cubic root of 11851681 is about 227.9956973129.

The spelling of 11851681 in words is "eleven million, eight hundred fifty-one thousand, six hundred eighty-one".