20018400220 has 216 divisors, whose sum is σ = 53530950816. Its totient is φ = 6232633344.

The previous prime is 20018400151. The next prime is 20018400277. The reversal of 20018400220 is 2200481002.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 119870577 + ... + 119870743.

It is an arithmetic number, because the mean of its divisors is an integer number (247828476).

Almost surely, 2^20018400220 is an apocalyptic number.

20018400220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20018400220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26765475408).

20018400220 is an abundant number, since it is smaller than the sum of its proper divisors (33512550596).

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

20018400220 is a wasteful number, since it uses less digits than its factorization.

20018400220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 397 (or 291 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 20018400220 its reverse (2200481002), we get a palindrome (22218881222).

The spelling of 20018400220 in words is "twenty billion, eighteen million, four hundred thousand, two hundred twenty".