56563981 has 8 divisors (see below), whose sum is σ = 59967864. Its totient is φ = 53168640.

The previous prime is 56563979. The next prime is 56563987. The reversal of 56563981 is 18936565.

It can be written as a sum of positive squares in 4 ways, for example, as 39175081 + 17388900 = 6259^2 + 4170^2 .

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 56563981 - 2¹ = 56563979 is a prime.

It is a super-2 number, since 2×56563981² = 6398967893136722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56563987) 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, 15951 + ... + 19171.

It is an arithmetic number, because the mean of its divisors is an integer number (7495983).

Almost surely, 2^56563981 is an apocalyptic number.

It is an amenable number.

56563981 is a deficient number, since it is larger than the sum of its proper divisors (3403883).

56563981 is a wasteful number, since it uses less digits than its factorization.

56563981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4271.

The product of its digits is 194400, while the sum is 43.

The square root of 56563981 is about 7520.9029378127. The cubic root of 56563981 is about 383.8663022875.

It can be divided in two parts, 565 and 63981, that added together give a palindrome (64546).

The spelling of 56563981 in words is "fifty-six million, five hundred sixty-three thousand, nine hundred eighty-one".