11865981 has 8 divisors (see below), whose sum is σ = 15937344. Its totient is φ = 7852640.

The previous prime is 11865967. The next prime is 11865989. The reversal of 11865981 is 18956811.

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 11865981 - 2⁷ = 11865853 is a prime.

It is a super-2 number, since 2×11865981² = 281603010184722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11865989) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14025 + ... + 14846.

It is an arithmetic number, because the mean of its divisors is an integer number (1992168).

Almost surely, 2^11865981 is an apocalyptic number.

It is an amenable number.

11865981 is a deficient number, since it is larger than the sum of its proper divisors (4071363).

11865981 is a wasteful number, since it uses less digits than its factorization.

11865981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29011.

The product of its digits is 17280, while the sum is 39.

The square root of 11865981 is about 3444.7033253968. The cubic root of 11865981 is about 228.0873587985.

The spelling of 11865981 in words is "eleven million, eight hundred sixty-five thousand, nine hundred eighty-one".