56545981 has 4 divisors (see below), whose sum is σ = 56670172. Its totient is φ = 56421792.

The previous prime is 56545943. The next prime is 56545987. The reversal of 56545981 is 18954565.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 47485881 + 9060100 = 6891^2 + 3010^2 .

It is a cyclic number.

It is not a de Polignac number, because 56545981 - 2²¹ = 54448829 is a prime.

It is a super-2 number, since 2×56545981² = 6394895934504722, 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 (56545987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61410 + ... + 62323.

It is an arithmetic number, because the mean of its divisors is an integer number (14167543).

Almost surely, 2^56545981 is an apocalyptic number.

It is an amenable number.

56545981 is a deficient number, since it is larger than the sum of its proper divisors (124191).

56545981 is a wasteful number, since it uses less digits than its factorization.

56545981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124190.

The product of its digits is 216000, while the sum is 43.

The square root of 56545981 is about 7519.7061777705. The cubic root of 56545981 is about 383.8255795143.

The spelling of 56545981 in words is "fifty-six million, five hundred forty-five thousand, nine hundred eighty-one".