420436638 has 24 divisors (see below), whose sum is σ = 923427648. Its totient is φ = 138225312.

The previous prime is 420436637. The next prime is 420436721. The reversal of 420436638 is 836634024.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (420436637) 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, 158670 + ... + 161297.

It is an arithmetic number, because the mean of its divisors is an integer number (38476152).

Almost surely, 2^420436638 is an apocalyptic number.

420436638 is an abundant number, since it is smaller than the sum of its proper divisors (502991010).

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

420436638 is a wasteful number, since it uses less digits than its factorization.

420436638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320048 (or 320045 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 36.

The square root of 420436638 is about 20504.5516410381. The cubic root of 420436638 is about 749.1466667982.

The spelling of 420436638 in words is "four hundred twenty million, four hundred thirty-six thousand, six hundred thirty-eight".