405857 has 2 divisors, whose sum is σ = 405858. Its totient is φ = 405856.

The previous prime is 405829. The next prime is 405863. The reversal of 405857 is 758504.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 309136 + 96721 = 556^2 + 311^2 .

It is a cyclic number.

It is not a de Polignac number, because 405857 - 2¹⁶ = 340321 is a prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 405857.

It is not a weakly prime, because it can be changed into another prime (405817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202928 + 202929.

It is an arithmetic number, because the mean of its divisors is an integer number (202929).

2⁴⁰⁵⁸⁵⁷ is an apocalyptic number.

It is an amenable number.

405857 is a deficient number, since it is larger than the sum of its proper divisors (1).

405857 is an equidigital number, since it uses as much as digits as its factorization.

405857 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5600, while the sum is 29.

The square root of 405857 is about 637.0690700387. The cubic root of 405857 is about 74.0385117289.

The spelling of 405857 in words is "four hundred five thousand, eight hundred fifty-seven".