1256766444 has 72 divisors (see below), whose sum is σ = 3226728960. Its totient is φ = 412375392.

The previous prime is 1256766397. The next prime is 1256766449. The reversal of 1256766444 is 4446676521.

It is a self number, because there is not a number n which added to its sum of digits gives 1256766444.

It is not an unprimeable number, because it can be changed into a prime (1256766449) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1839727 + ... + 1840409.

It is an arithmetic number, because the mean of its divisors is an integer number (44815680).

Almost surely, 2^1256766444 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1256766444, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1613364480).

1256766444 is an abundant number, since it is smaller than the sum of its proper divisors (1969962516).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1256766444 is a wasteful number, since it uses less digits than its factorization.

1256766444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1419 (or 1414 counting only the distinct ones).

The product of its digits is 967680, while the sum is 45.

The square root of 1256766444 is about 35450.9018785136. The cubic root of 1256766444 is about 1079.1575632061.

The spelling of 1256766444 in words is "one billion, two hundred fifty-six million, seven hundred sixty-six thousand, four hundred forty-four".