1256523287 has 2 divisors, whose sum is σ = 1256523288. Its totient is φ = 1256523286.

The previous prime is 1256523263. The next prime is 1256523337. The reversal of 1256523287 is 7823256521.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1256523287 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1256123287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628261643 + 628261644.

It is an arithmetic number, because the mean of its divisors is an integer number (628261644).

Almost surely, 2^1256523287 is an apocalyptic number.

1256523287 is a deficient number, since it is larger than the sum of its proper divisors (1).

1256523287 is an equidigital number, since it uses as much as digits as its factorization.

1256523287 is an evil number, because the sum of its binary digits is even.

The product of its digits is 201600, while the sum is 41.

The square root of 1256523287 is about 35447.4722229950. The cubic root of 1256523287 is about 1079.0879608702.

The spelling of 1256523287 in words is "one billion, two hundred fifty-six million, five hundred twenty-three thousand, two hundred eighty-seven".