840457 has 2 divisors, whose sum is σ = 840458. Its totient is φ = 840456.

The previous prime is 840451. The next prime is 840467. The reversal of 840457 is 754048.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 594441 + 246016 = 771^2 + 496^2 .

It is a cyclic number.

It is not a de Polignac number, because 840457 - 2¹⁵ = 807689 is a prime.

It is a pancake number, because a pancake can be divided into 840457 parts by 1296 straight cuts.

It is not a weakly prime, because it can be changed into another prime (840451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 420228 + 420229.

It is an arithmetic number, because the mean of its divisors is an integer number (420229).

2⁸⁴⁰⁴⁵⁷ is an apocalyptic number.

It is an amenable number.

840457 is a deficient number, since it is larger than the sum of its proper divisors (1).

840457 is an equidigital number, since it uses as much as digits as its factorization.

840457 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4480, while the sum is 28.

The square root of 840457 is about 916.7644190303. The cubic root of 840457 is about 94.3709875054.

The spelling of 840457 in words is "eight hundred forty thousand, four hundred fifty-seven".