6394256440 has 64 divisors (see below), whose sum is σ = 16902315360. Its totient is φ = 2146321920.

The previous prime is 6394256383. The next prime is 6394256443. The reversal of 6394256440 is 446524936.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6394256443) 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, 553219 + ... + 564658.

Almost surely, 2^6394256440 is an apocalyptic number.

It is an amenable number.

6394256440 is an abundant number, since it is smaller than the sum of its proper divisors (10508058920).

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

6394256440 is a wasteful number, since it uses less digits than its factorization.

6394256440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1117912 (or 1117908 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 43.

The square root of 6394256440 is about 79964.0946925556. The cubic root of 6394256440 is about 1856.0799663017.

The spelling of 6394256440 in words is "six billion, three hundred ninety-four million, two hundred fifty-six thousand, four hundred forty".