11955981 has 8 divisors (see below), whose sum is σ = 16879104. Its totient is φ = 7501760.

The previous prime is 11955973. The next prime is 11955989. The reversal of 11955981 is 18955911.

It is an interprime number because it is at equal distance from previous prime (11955973) and next prime (11955989).

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

It is not a de Polignac number, because 11955981 - 2³ = 11955973 is a prime.

It is a super-2 number, since 2×11955981² = 285890963344722, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11955989) 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, 117165 + ... + 117266.

It is an arithmetic number, because the mean of its divisors is an integer number (2109888).

Almost surely, 2^11955981 is an apocalyptic number.

It is an amenable number.

11955981 is a deficient number, since it is larger than the sum of its proper divisors (4923123).

11955981 is a wasteful number, since it uses less digits than its factorization.

11955981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234451.

The product of its digits is 16200, while the sum is 39.

The square root of 11955981 is about 3457.7421824075. The cubic root of 11955981 is about 228.6625656469.

The spelling of 11955981 in words is "eleven million, nine hundred fifty-five thousand, nine hundred eighty-one".