1256776531 has 2 divisors, whose sum is σ = 1256776532. Its totient is φ = 1256776530.

The previous prime is 1256776529. The next prime is 1256776559. The reversal of 1256776531 is 1356776521.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1256776531 - 2¹ = 1256776529 is a prime.

It is a super-2 number, since 2×1256776531² = 3158974497744787922, which contains 22 as substring.

Together with 1256776529, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1256776231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628388265 + 628388266.

It is an arithmetic number, because the mean of its divisors is an integer number (628388266).

Almost surely, 2^1256776531 is an apocalyptic number.

1256776531 is a deficient number, since it is larger than the sum of its proper divisors (1).

1256776531 is an equidigital number, since it uses as much as digits as its factorization.

1256776531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 264600, while the sum is 43.

The square root of 1256776531 is about 35451.0441454127. The cubic root of 1256776531 is about 1079.1604503597.

It can be divided in two parts, 12567 and 76531, that added together give a palindrome (89098).

The spelling of 1256776531 in words is "one billion, two hundred fifty-six million, seven hundred seventy-six thousand, five hundred thirty-one".