421220639858 has 18 divisors (see below), whose sum is σ = 637939847181. Its totient is φ = 208593353344.

The previous prime is 421220639789. The next prime is 421220639869. The reversal of 421220639858 is 858936022124.

It can be written as a sum of positive squares in 2 ways, for example, as 309700041049 + 111520598809 = 556507^2 + 333947^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=458923.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 98207378 + ... + 98211666.

Almost surely, 2^421220639858 is an apocalyptic number.

421220639858 is a deficient number, since it is larger than the sum of its proper divisors (216719207323).

421220639858 is an frugal number, since it uses more digits than its factorization.

421220639858 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8794 (or 4398 counting only the distinct ones).

The product of its (nonzero) digits is 1658880, while the sum is 50.

Multiplying 421220639858 by its sum of digits (50), we get a square (21061031992900 = 4589230²).

The spelling of 421220639858 in words is "four hundred twenty-one billion, two hundred twenty million, six hundred thirty-nine thousand, eight hundred fifty-eight".