56278021 has 2 divisors, whose sum is σ = 56278022. Its totient is φ = 56278020.

The previous prime is 56278003. The next prime is 56278037. The reversal of 56278021 is 12087265.

56278021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 34093921 + 22184100 = 5839^2 + 4710^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-56278021 is a prime.

It is equal to p_3353980 and since 56278021 and 3353980 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56270021) 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, 28139010 + 28139011.

It is an arithmetic number, because the mean of its divisors is an integer number (28139011).

Almost surely, 2^56278021 is an apocalyptic number.

It is an amenable number.

56278021 is a deficient number, since it is larger than the sum of its proper divisors (1).

56278021 is an equidigital number, since it uses as much as digits as its factorization.

56278021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6720, while the sum is 31.

The square root of 56278021 is about 7501.8678340797. The cubic root of 56278021 is about 383.2183286176.

The spelling of 56278021 in words is "fifty-six million, two hundred seventy-eight thousand, twenty-one".