21123020020200 has 384 divisors, whose sum is σ = 78800992128000. Its totient is φ = 4572473241600.

The previous prime is 21123020020169. The next prime is 21123020020273. The reversal of 21123020020200 is 202002032112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21123020020200.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 246459355 + ... + 246545045.

It is an arithmetic number, because the mean of its divisors is an integer number (205210917000).

Almost surely, 2^{21123020020200} is an apocalyptic number.

21123020020200 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 21123020020200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39400496064000).

21123020020200 is an abundant number, since it is smaller than the sum of its proper divisors (57677972107800).

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

21123020020200 is a wasteful number, since it uses less digits than its factorization.

21123020020200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88825 (or 88816 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

Adding to 21123020020200 its reverse (202002032112), we get a palindrome (21325022052312).

The spelling of 21123020020200 in words is "twenty-one trillion, one hundred twenty-three billion, twenty million, twenty thousand, two hundred".