420135257 has 2 divisors, whose sum is σ = 420135258. Its totient is φ = 420135256.

The previous prime is 420135253. The next prime is 420135307. The reversal of 420135257 is 752531024.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 413064976 + 7070281 = 20324^2 + 2659^2 .

It is a cyclic number.

It is not a de Polignac number, because 420135257 - 2² = 420135253 is a prime.

It is not a weakly prime, because it can be changed into another prime (420135253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210067628 + 210067629.

It is an arithmetic number, because the mean of its divisors is an integer number (210067629).

Almost surely, 2^420135257 is an apocalyptic number.

It is an amenable number.

420135257 is a deficient number, since it is larger than the sum of its proper divisors (1).

420135257 is an equidigital number, since it uses as much as digits as its factorization.

420135257 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8400, while the sum is 29.

The square root of 420135257 is about 20497.2011991881. The cubic root of 420135257 is about 748.9676207614.

The spelling of 420135257 in words is "four hundred twenty million, one hundred thirty-five thousand, two hundred fifty-seven".