840459857 has 2 divisors, whose sum is σ = 840459858. Its totient is φ = 840459856.

The previous prime is 840459853. The next prime is 840459863. The reversal of 840459857 is 758954048.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 628204096 + 212255761 = 25064^2 + 14569^2 .

It is a cyclic number.

It is not a de Polignac number, because 840459857 - 2² = 840459853 is a prime.

It is not a weakly prime, because it can be changed into another prime (840459853) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 420229928 + 420229929.

It is an arithmetic number, because the mean of its divisors is an integer number (420229929).

Almost surely, 2^840459857 is an apocalyptic number.

It is an amenable number.

840459857 is a deficient number, since it is larger than the sum of its proper divisors (1).

840459857 is an equidigital number, since it uses as much as digits as its factorization.

840459857 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1612800, while the sum is 50.

The square root of 840459857 is about 28990.6856938569. The cubic root of 840459857 is about 943.7109443832.

The spelling of 840459857 in words is "eight hundred forty million, four hundred fifty-nine thousand, eight hundred fifty-seven".