11681381 has 8 divisors (see below), whose sum is σ = 12040224. Its totient is φ = 11324880.

The previous prime is 11681353. The next prime is 11681399. The reversal of 11681381 is 18318611.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 11681381 - 2¹⁸ = 11419237 is a prime.

It is a super-2 number, since 2×11681381² = 272909324134322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11681311) 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 7 ways as a sum of consecutive naturals, for example, 17846 + ... + 18488.

It is an arithmetic number, because the mean of its divisors is an integer number (1505028).

Almost surely, 2^11681381 is an apocalyptic number.

It is an amenable number.

11681381 is a deficient number, since it is larger than the sum of its proper divisors (358843).

11681381 is an equidigital number, since it uses as much as digits as its factorization.

11681381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1171.

The product of its digits is 1152, while the sum is 29.

The square root of 11681381 is about 3417.8035344355. The cubic root of 11681381 is about 226.8983806446.

Adding to 11681381 its reverse (18318611), we get a palindrome (29999992).

The spelling of 11681381 in words is "eleven million, six hundred eighty-one thousand, three hundred eighty-one".