56156256421 has 2 divisors, whose sum is σ = 56156256422. Its totient is φ = 56156256420.

The previous prime is 56156256391. The next prime is 56156256469. The reversal of 56156256421 is 12465265165.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 46866188196 + 9290068225 = 216486^2 + 96385^2 .

It is a cyclic number.

It is not a de Polignac number, because 56156256421 - 2¹³ = 56156248229 is a prime.

It is a super-2 number, since 2×56156256421² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56156256491) 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 as a sum of consecutive naturals, namely, 28078128210 + 28078128211.

It is an arithmetic number, because the mean of its divisors is an integer number (28078128211).

Almost surely, 2^56156256421 is an apocalyptic number.

It is an amenable number.

56156256421 is a deficient number, since it is larger than the sum of its proper divisors (1).

56156256421 is an equidigital number, since it uses as much as digits as its factorization.

56156256421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 432000, while the sum is 43.

The spelling of 56156256421 in words is "fifty-six billion, one hundred fifty-six million, two hundred fifty-six thousand, four hundred twenty-one".