420720660 has 72 divisors (see below), whose sum is σ = 1297140936. Its totient is φ = 110350080.

The previous prime is 420720659. The next prime is 420720679. The reversal of 420720660 is 66027024.

It can be written as a sum of positive squares in 4 ways, for example, as 3825936 + 416894724 = 1956^2 + 20418^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8179 + ... + 30138.

Almost surely, 2^420720660 is an apocalyptic number.

It is an amenable number.

420720660 is an abundant number, since it is smaller than the sum of its proper divisors (876420276).

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

420720660 is a wasteful number, since it uses less digits than its factorization.

420720660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38393 (or 38388 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 27.

The square root of 420720660 is about 20511.4762998669. The cubic root of 420720660 is about 749.3153218112.

Adding to 420720660 its reverse (66027024), we get a palindrome (486747684).

The spelling of 420720660 in words is "four hundred twenty million, seven hundred twenty thousand, six hundred sixty".