56071981 has 8 divisors (see below), whose sum is σ = 64174464. Its totient is φ = 47992560.

The previous prime is 56071979. The next prime is 56071991. The reversal of 56071981 is 18917065.

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

It is not a de Polignac number, because 56071981 - 2¹ = 56071979 is a prime.

It is a super-2 number, since 2×56071981² = 6288134106528722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 56071981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56071921) 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, 190 + ... + 10591.

It is an arithmetic number, because the mean of its divisors is an integer number (8021808).

Almost surely, 2^56071981 is an apocalyptic number.

It is an amenable number.

56071981 is a deficient number, since it is larger than the sum of its proper divisors (8102483).

56071981 is a wasteful number, since it uses less digits than its factorization.

56071981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11531.

The product of its (nonzero) digits is 15120, while the sum is 37.

The square root of 56071981 is about 7488.1226619227. The cubic root of 56071981 is about 382.7500886320.

The spelling of 56071981 in words is "fifty-six million, seventy-one thousand, nine hundred eighty-one".