420356639 has 2 divisors, whose sum is σ = 420356640. Its totient is φ = 420356638.

The previous prime is 420356623. The next prime is 420356687. The reversal of 420356639 is 936653024.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 420356639 - 2⁴ = 420356623 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (420356539) 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, 210178319 + 210178320.

It is an arithmetic number, because the mean of its divisors is an integer number (210178320).

Almost surely, 2^420356639 is an apocalyptic number.

420356639 is a deficient number, since it is larger than the sum of its proper divisors (1).

420356639 is an equidigital number, since it uses as much as digits as its factorization.

420356639 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 116640, while the sum is 38.

The square root of 420356639 is about 20502.6007862417. The cubic root of 420356639 is about 749.0991489082.

The spelling of 420356639 in words is "four hundred twenty million, three hundred fifty-six thousand, six hundred thirty-nine".