20400244220 has 48 divisors (see below), whose sum is σ = 44718524928. Its totient is φ = 7802625600.

The previous prime is 20400244211. The next prime is 20400244223. The reversal of 20400244220 is 2244200402.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 20400244192 and 20400244201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20400244223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1791545 + ... + 1802895.

It is an arithmetic number, because the mean of its divisors is an integer number (931635936).

Almost surely, 2^20400244220 is an apocalyptic number.

20400244220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20400244220 is an abundant number, since it is smaller than the sum of its proper divisors (24318280708).

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

20400244220 is a wasteful number, since it uses less digits than its factorization.

20400244220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15290 (or 15288 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 20.

Adding to 20400244220 its reverse (2244200402), we get a palindrome (22644444622).

The spelling of 20400244220 in words is "twenty billion, four hundred million, two hundred forty-four thousand, two hundred twenty".