56421557 has 2 divisors, whose sum is σ = 56421558. Its totient is φ = 56421556.

The previous prime is 56421503. The next prime is 56421577. The reversal of 56421557 is 75512465.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 34975396 + 21446161 = 5914^2 + 4631^2 .

It is a cyclic number.

It is not a de Polignac number, because 56421557 - 2⁶ = 56421493 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56421577) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28210778 + 28210779.

It is an arithmetic number, because the mean of its divisors is an integer number (28210779).

Almost surely, 2^56421557 is an apocalyptic number.

It is an amenable number.

56421557 is a deficient number, since it is larger than the sum of its proper divisors (1).

56421557 is an equidigital number, since it uses as much as digits as its factorization.

56421557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 42000, while the sum is 35.

The square root of 56421557 is about 7511.4284260718. The cubic root of 56421557 is about 383.5438489990.

The spelling of 56421557 in words is "fifty-six million, four hundred twenty-one thousand, five hundred fifty-seven".