840256851 has 48 divisors (see below), whose sum is σ = 1340997504. Its totient is φ = 466373376.

The previous prime is 840256801. The next prime is 840256867. The reversal of 840256851 is 158652048.

It is not a de Polignac number, because 840256851 - 2¹³ = 840248659 is a prime.

It is not an unprimeable number, because it can be changed into a prime (840256801) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1940331 + ... + 1940763.

It is an arithmetic number, because the mean of its divisors is an integer number (27937448).

Almost surely, 2^840256851 is an apocalyptic number.

840256851 is a deficient number, since it is larger than the sum of its proper divisors (500740653).

840256851 is a wasteful number, since it uses less digits than its factorization.

840256851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 800 (or 793 counting only the distinct ones).

The product of its (nonzero) digits is 76800, while the sum is 39.

The square root of 840256851 is about 28987.1842544253. The cubic root of 840256851 is about 943.6349564546.

The spelling of 840256851 in words is "eight hundred forty million, two hundred fifty-six thousand, eight hundred fifty-one".