56201681 has 4 divisors (see below), whose sum is σ = 58139700. Its totient is φ = 54263664.

The previous prime is 56201671. The next prime is 56201701. The reversal of 56201681 is 18610265.

It is a happy number.

56201681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18610265 = 5 ⋅3722053.

It can be written as a sum of positive squares in 2 ways, for example, as 10504081 + 45697600 = 3241^2 + 6760^2 .

It is a cyclic number.

It is not a de Polignac number, because 56201681 - 2⁶ = 56201617 is a prime.

It is a super-2 number, since 2×56201681² = 6317257894451522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (29), and also a Moran number because the ratio is a prime number: 1937989 = 56201681 / (5 + 6 + 2 + 0 + 1 + 6 + 8 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (56201671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 968966 + ... + 969023.

It is an arithmetic number, because the mean of its divisors is an integer number (14534925).

Almost surely, 2^56201681 is an apocalyptic number.

It is an amenable number.

56201681 is a deficient number, since it is larger than the sum of its proper divisors (1938019).

56201681 is a wasteful number, since it uses less digits than its factorization.

56201681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1938018.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 56201681 is about 7496.7780412655. The cubic root of 56201681 is about 383.0449742331.

The spelling of 56201681 in words is "fifty-six million, two hundred one thousand, six hundred eighty-one".