20820420660 has 96 divisors (see below), whose sum is σ = 64946528640. Its totient is φ = 4948296192.

The previous prime is 20820420623. The next prime is 20820420671. The reversal of 20820420660 is 6602402802.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 437602 + ... + 482841.

It is an arithmetic number, because the mean of its divisors is an integer number (676526340).

Almost surely, 2^20820420660 is an apocalyptic number.

20820420660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20820420660 is an abundant number, since it is smaller than the sum of its proper divisors (44126107980).

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

20820420660 is a wasteful number, since it uses less digits than its factorization.

20820420660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 920497 (or 920495 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 30.

The spelling of 20820420660 in words is "twenty billion, eight hundred twenty million, four hundred twenty thousand, six hundred sixty".