420688638 has 24 divisors (see below), whose sum is σ = 912501408. Its totient is φ = 140074272.

The previous prime is 420688637. The next prime is 420688649. The reversal of 420688638 is 836886024.

It is a happy number.

420688638 is a `hidden beast` number, since 4 + 2 + 0 + 6 + 8 + 8 + 638 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 420688593 and 420688602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (420688637) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4395 + ... + 29337.

It is an arithmetic number, because the mean of its divisors is an integer number (38020892).

Almost surely, 2^420688638 is an apocalyptic number.

420688638 is an abundant number, since it is smaller than the sum of its proper divisors (491812770).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

420688638 is a wasteful number, since it uses less digits than its factorization.

420688638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25888 (or 25885 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 45.

The square root of 420688638 is about 20510.6956976110. The cubic root of 420688638 is about 749.2963106349.

The spelling of 420688638 in words is "four hundred twenty million, six hundred eighty-eight thousand, six hundred thirty-eight".