56130721 has 2 divisors, whose sum is σ = 56130722. Its totient is φ = 56130720.

The previous prime is 56130713. The next prime is 56130743. The reversal of 56130721 is 12703165.

56130721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55726225 + 404496 = 7465^2 + 636^2 .

It is a cyclic number.

It is not a de Polignac number, because 56130721 - 2³ = 56130713 is a prime.

It is not a weakly prime, because it can be changed into another prime (56130421) 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 as a sum of consecutive naturals, namely, 28065360 + 28065361.

It is an arithmetic number, because the mean of its divisors is an integer number (28065361).

Almost surely, 2^56130721 is an apocalyptic number.

It is an amenable number.

56130721 is a deficient number, since it is larger than the sum of its proper divisors (1).

56130721 is an equidigital number, since it uses as much as digits as its factorization.

56130721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1260, while the sum is 25.

The square root of 56130721 is about 7492.0438466416. The cubic root of 56130721 is about 382.8836960270.

Adding to 56130721 its reverse (12703165), we get a palindrome (68833886).

The spelling of 56130721 in words is "fifty-six million, one hundred thirty thousand, seven hundred twenty-one".