840256440 has 64 divisors (see below), whose sum is σ = 2607703200. Its totient is φ = 216340992.

The previous prime is 840256427. The next prime is 840256441. The reversal of 840256440 is 44652048.

It is a super-3 number, since 3×840256440³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (840256441) 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, 117247 + ... + 124206.

Almost surely, 2^840256440 is an apocalyptic number.

It is an amenable number.

840256440 is an abundant number, since it is smaller than the sum of its proper divisors (1767446760).

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

840256440 is a wasteful number, since it uses less digits than its factorization.

840256440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241496 (or 241492 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 33.

The square root of 840256440 is about 28987.1771650846. The cubic root of 840256440 is about 943.6348025993.

The spelling of 840256440 in words is "eight hundred forty million, two hundred fifty-six thousand, four hundred forty".