1256741647 has 16 divisors (see below), whose sum is σ = 1460876032. Its totient is φ = 1058857920.

The previous prime is 1256741641. The next prime is 1256741657. The reversal of 1256741647 is 7461476521.

It is a cyclic number.

It is not a de Polignac number, because 1256741647 - 2¹⁵ = 1256708879 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1256741641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 152872 + ... + 160882.

It is an arithmetic number, because the mean of its divisors is an integer number (91304752).

Almost surely, 2^1256741647 is an apocalyptic number.

1256741647 is a deficient number, since it is larger than the sum of its proper divisors (204134385).

1256741647 is an equidigital number, since it uses as much as digits as its factorization.

1256741647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8398.

The product of its digits is 282240, while the sum is 43.

The square root of 1256741647 is about 35450.5521395648. The cubic root of 1256741647 is about 1079.1504656141.

The spelling of 1256741647 in words is "one billion, two hundred fifty-six million, seven hundred forty-one thousand, six hundred forty-seven".