20400220020 has 24 divisors (see below), whose sum is σ = 57120616224. Its totient is φ = 5440058656.

The previous prime is 20400219971. The next prime is 20400220033. The reversal of 20400220020 is 2002200402.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 20400219978 and 20400220005.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 170001774 + ... + 170001893.

It is an arithmetic number, because the mean of its divisors is an integer number (2380025676).

Almost surely, 2^20400220020 is an apocalyptic number.

20400220020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20400220020 is an abundant number, since it is smaller than the sum of its proper divisors (36720396204).

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

20400220020 is a wasteful number, since it uses less digits than its factorization.

20400220020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340003679 (or 340003677 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 12.

Adding to 20400220020 its reverse (2002200402), we get a palindrome (22402420422).

The spelling of 20400220020 in words is "twenty billion, four hundred million, two hundred twenty thousand, twenty".