556051021 has 2 divisors, whose sum is σ = 556051022. Its totient is φ = 556051020.

The previous prime is 556051019. The next prime is 556051063. The reversal of 556051021 is 120150655.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 541074121 + 14976900 = 23261^2 + 3870^2 .

It is a cyclic number.

It is not a de Polignac number, because 556051021 - 2¹ = 556051019 is a prime.

Together with 556051019, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (556051121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 278025510 + 278025511.

It is an arithmetic number, because the mean of its divisors is an integer number (278025511).

Almost surely, 2^556051021 is an apocalyptic number.

It is an amenable number.

556051021 is a deficient number, since it is larger than the sum of its proper divisors (1).

556051021 is an equidigital number, since it uses as much as digits as its factorization.

556051021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1500, while the sum is 25.

The square root of 556051021 is about 23580.7341064692. The cubic root of 556051021 is about 822.3150034013.

The spelling of 556051021 in words is "five hundred fifty-six million, fifty-one thousand, twenty-one".