1256744138 has 16 divisors (see below), whose sum is σ = 2042288640. Its totient is φ = 576560496.

The previous prime is 1256744131. The next prime is 1256744147. The reversal of 1256744138 is 8314476521.

It is a junction number, because it is equal to n+sod(n) for n = 1256744095 and 1256744104.

It is not an unprimeable number, because it can be changed into a prime (1256744131) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 140378 + ... + 149061.

It is an arithmetic number, because the mean of its divisors is an integer number (127643040).

Almost surely, 2^1256744138 is an apocalyptic number.

1256744138 is a deficient number, since it is larger than the sum of its proper divisors (785544502).

1256744138 is a wasteful number, since it uses less digits than its factorization.

1256744138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 289621.

The product of its digits is 161280, while the sum is 41.

The square root of 1256744138 is about 35450.5872729917. The cubic root of 1256744138 is about 1079.1511786119.

The spelling of 1256744138 in words is "one billion, two hundred fifty-six million, seven hundred forty-four thousand, one hundred thirty-eight".