256421827 has 2 divisors, whose sum is σ = 256421828. Its totient is φ = 256421826.

The previous prime is 256421819. The next prime is 256421833. The reversal of 256421827 is 728124652.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 256421827 - 2³ = 256421819 is a prime.

It is not a weakly prime, because it can be changed into another prime (256421887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128210913 + 128210914.

It is an arithmetic number, because the mean of its divisors is an integer number (128210914).

Almost surely, 2^256421827 is an apocalyptic number.

256421827 is a deficient number, since it is larger than the sum of its proper divisors (1).

256421827 is an equidigital number, since it uses as much as digits as its factorization.

256421827 is an evil number, because the sum of its binary digits is even.

The product of its digits is 53760, while the sum is 37.

The square root of 256421827 is about 16013.1766679819. The cubic root of 256421827 is about 635.3089838991.

The spelling of 256421827 in words is "two hundred fifty-six million, four hundred twenty-one thousand, eight hundred twenty-seven".