21200124220 has 96 divisors (see below), whose sum is σ = 49855684032. Its totient is φ = 7507200000.

The previous prime is 21200124217. The next prime is 21200124223. The reversal of 21200124220 is 2242100212.

It is an interprime number because it is at equal distance from previous prime (21200124217) and next prime (21200124223).

It is a junction number, because it is equal to n+sod(n) for n = 21200124194 and 21200124203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21200124223) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1347600 + ... + 1363240.

It is an arithmetic number, because the mean of its divisors is an integer number (519330042).

Almost surely, 2^21200124220 is an apocalyptic number.

21200124220 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 21200124220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24927842016).

21200124220 is an abundant number, since it is smaller than the sum of its proper divisors (28655559812).

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

21200124220 is a wasteful number, since it uses less digits than its factorization.

21200124220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15823 (or 15821 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 21200124220 its reverse (2242100212), we get a palindrome (23442224432).

The spelling of 21200124220 in words is "twenty-one billion, two hundred million, one hundred twenty-four thousand, two hundred twenty".