420621633640 has 32 divisors (see below), whose sum is σ = 1019198575080. Its totient is φ = 155306449152.

The previous prime is 420621633539. The next prime is 420621633647. The reversal of 420621633640 is 46336126024.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 370907796484 + 49713837156 = 609022^2 + 222966^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 420621633640.

It is not an unprimeable number, because it can be changed into a prime (420621633647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 404443359 + ... + 404444398.

Almost surely, 2^420621633640 is an apocalyptic number.

420621633640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

420621633640 is an abundant number, since it is smaller than the sum of its proper divisors (598576941440).

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

420621633640 is a wasteful number, since it uses less digits than its factorization.

420621633640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 808887781 (or 808887777 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 37.

Adding to 420621633640 its reverse (46336126024), we get a palindrome (466957759664).

The spelling of 420621633640 in words is "four hundred twenty billion, six hundred twenty-one million, six hundred thirty-three thousand, six hundred forty".