1256779438 has 16 divisors (see below), whose sum is σ = 1953020160. Its totient is φ = 605836000.

The previous prime is 1256779429. The next prime is 1256779439. The reversal of 1256779438 is 8349776521.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1256779439) 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, 25203 + ... + 56113.

It is an arithmetic number, because the mean of its divisors is an integer number (122063760).

Almost surely, 2^1256779438 is an apocalyptic number.

1256779438 is a deficient number, since it is larger than the sum of its proper divisors (696240722).

1256779438 is a wasteful number, since it uses less digits than its factorization.

1256779438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31643.

The product of its digits is 2540160, while the sum is 52.

The square root of 1256779438 is about 35451.0851455918. The cubic root of 1256779438 is about 1079.1612824134.

The spelling of 1256779438 in words is "one billion, two hundred fifty-six million, seven hundred seventy-nine thousand, four hundred thirty-eight".