1256675729 has 2 divisors, whose sum is σ = 1256675730. Its totient is φ = 1256675728.

The previous prime is 1256675681. The next prime is 1256675759. The reversal of 1256675729 is 9275766521.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1233414400 + 23261329 = 35120^2 + 4823^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1256675729 is a prime.

It is not a weakly prime, because it can be changed into another prime (1256675759) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628337864 + 628337865.

It is an arithmetic number, because the mean of its divisors is an integer number (628337865).

Almost surely, 2^1256675729 is an apocalyptic number.

It is an amenable number.

1256675729 is a deficient number, since it is larger than the sum of its proper divisors (1).

1256675729 is an equidigital number, since it uses as much as digits as its factorization.

1256675729 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1587600, while the sum is 50.

The square root of 1256675729 is about 35449.6224098368. The cubic root of 1256675729 is about 1079.1315975929.

The spelling of 1256675729 in words is "one billion, two hundred fifty-six million, six hundred seventy-five thousand, seven hundred twenty-nine".