1256645764 has 24 divisors (see below), whose sum is σ = 2402836128. Its totient is φ = 570301440.

The previous prime is 1256645749. The next prime is 1256645773. The reversal of 1256645764 is 4675466521.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6084 + ... + 50500.

It is an arithmetic number, because the mean of its divisors is an integer number (100118172).

Almost surely, 2^1256645764 is an apocalyptic number.

It is an amenable number.

1256645764 is a deficient number, since it is larger than the sum of its proper divisors (1146190364).

1256645764 is a wasteful number, since it uses less digits than its factorization.

1256645764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45075 (or 45073 counting only the distinct ones).

The product of its digits is 1209600, while the sum is 46.

The square root of 1256645764 is about 35449.1997652979. The cubic root of 1256645764 is about 1079.1230203510.

It can be divided in two parts, 12566457 and 64, that added together give a palindrome (12566521).

The spelling of 1256645764 in words is "one billion, two hundred fifty-six million, six hundred forty-five thousand, seven hundred sixty-four".