3111981 has 4 divisors (see below), whose sum is σ = 4149312. Its totient is φ = 2074652.

The previous prime is 3111973. The next prime is 3112007. The reversal of 3111981 is 1891113.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 3111981 - 2³ = 3111973 is a prime.

It is a super-2 number, since 2×3111981² = 19368851488722, which contains 22 as substring.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3111931) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 518661 + ... + 518666.

It is an arithmetic number, because the mean of its divisors is an integer number (1037328).

Almost surely, 2^3111981 is an apocalyptic number.

It is an amenable number.

3111981 is a deficient number, since it is larger than the sum of its proper divisors (1037331).

3111981 is a wasteful number, since it uses less digits than its factorization.

3111981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1037330.

The product of its digits is 216, while the sum is 24.

The square root of 3111981 is about 1764.0807804633. The cubic root of 3111981 is about 145.9975761154.

The spelling of 3111981 in words is "three million, one hundred eleven thousand, nine hundred eighty-one".