256497187 has 2 divisors, whose sum is σ = 256497188. Its totient is φ = 256497186.

The previous prime is 256497161. The next prime is 256497211. The reversal of 256497187 is 781794652.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 256497187 - 2²³ = 248108579 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 256497187.

It is not a weakly prime, because it can be changed into another prime (256497287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128248593 + 128248594.

It is an arithmetic number, because the mean of its divisors is an integer number (128248594).

Almost surely, 2^256497187 is an apocalyptic number.

256497187 is a deficient number, since it is larger than the sum of its proper divisors (1).

256497187 is an equidigital number, since it uses as much as digits as its factorization.

256497187 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 846720, while the sum is 49.

The square root of 256497187 is about 16015.5295572766. The cubic root of 256497187 is about 635.3712149452.

The spelling of 256497187 in words is "two hundred fifty-six million, four hundred ninety-seven thousand, one hundred eighty-seven".