256553491 has 2 divisors, whose sum is σ = 256553492. Its totient is φ = 256553490.

The previous prime is 256553483. The next prime is 256553501. The reversal of 256553491 is 194355652.

256553491 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 256553491 - 2³ = 256553483 is a prime.

It is not a weakly prime, because it can be changed into another prime (256553471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128276745 + 128276746.

It is an arithmetic number, because the mean of its divisors is an integer number (128276746).

Almost surely, 2^256553491 is an apocalyptic number.

256553491 is a deficient number, since it is larger than the sum of its proper divisors (1).

256553491 is an equidigital number, since it uses as much as digits as its factorization.

256553491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 162000, while the sum is 40.

The square root of 256553491 is about 16017.2872547133. The cubic root of 256553491 is about 635.4177019054.

The spelling of 256553491 in words is "two hundred fifty-six million, five hundred fifty-three thousand, four hundred ninety-one".