56581281 has 16 divisors (see below), whose sum is σ = 83963520. Its totient is φ = 37658160.

The previous prime is 56581243. The next prime is 56581303. The reversal of 56581281 is 18218565.

56581281 is a `hidden beast` number, since 56 + 581 + 28 + 1 = 666.

It is not a de Polignac number, because 56581281 - 2¹⁰ = 56580257 is a prime.

It is a super-2 number, since 2×56581281² = 6402882719201922, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (56581211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19516 + ... + 22226.

It is an arithmetic number, because the mean of its divisors is an integer number (5247720).

Almost surely, 2^56581281 is an apocalyptic number.

It is an amenable number.

56581281 is a deficient number, since it is larger than the sum of its proper divisors (27382239).

56581281 is a wasteful number, since it uses less digits than its factorization.

56581281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3493 (or 3487 counting only the distinct ones).

The product of its digits is 19200, while the sum is 36.

The square root of 56581281 is about 7522.0529777448. The cubic root of 56581281 is about 383.9054332562.

The spelling of 56581281 in words is "fifty-six million, five hundred eighty-one thousand, two hundred eighty-one".