420857 has 2 divisors, whose sum is σ = 420858. Its totient is φ = 420856.

The previous prime is 420853. The next prime is 420859. The reversal of 420857 is 758024.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 241081 + 179776 = 491^2 + 424^2 .

It is a cyclic number.

It is not a de Polignac number, because 420857 - 2² = 420853 is a prime.

It is a super-2 number, since 2×420857² = 354241228898, which contains 22 as substring.

Together with 420859, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (420851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210428 + 210429.

It is an arithmetic number, because the mean of its divisors is an integer number (210429).

2⁴²⁰⁸⁵⁷ is an apocalyptic number.

It is an amenable number.

420857 is a deficient number, since it is larger than the sum of its proper divisors (1).

420857 is an equidigital number, since it uses as much as digits as its factorization.

420857 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2240, while the sum is 26.

The square root of 420857 is about 648.7349227535. The cubic root of 420857 is about 74.9396254860.

The spelling of 420857 in words is "four hundred twenty thousand, eight hundred fifty-seven".