56981 has 4 divisors (see below), whose sum is σ = 60000. Its totient is φ = 53964.

The previous prime is 56963. The next prime is 56983. The reversal of 56981 is 18965.

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, and also an emirpimes, since its reverse is a distinct semiprime: 18965 = 5 ⋅3793.

It is a cyclic number.

It is not a de Polignac number, because 56981 - 2¹⁴ = 40597 is a prime.

It is a super-2 number, since 2×56981² = 6493668722, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 56981.

It is not an unprimeable number, because it can be changed into a prime (56983) 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, 1481 + ... + 1518.

It is an arithmetic number, because the mean of its divisors is an integer number (15000).

2⁵⁶⁹⁸¹ is an apocalyptic number.

It is an amenable number.

56981 is a deficient number, since it is larger than the sum of its proper divisors (3019).

56981 is a wasteful number, since it uses less digits than its factorization.

56981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3018.

The product of its digits is 2160, while the sum is 29.

The square root of 56981 is about 238.7069332885. The cubic root of 56981 is about 38.4807347252.

The spelling of 56981 in words is "fifty-six thousand, nine hundred eighty-one".