21200000121100 has 36 divisors (see below), whose sum is σ = 48004174192464. Its totient is φ = 8111304393280.

The previous prime is 21200000121037. The next prime is 21200000121149. The reversal of 21200000121100 is 112100000212.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4608693379 + ... + 4608697978.

It is an arithmetic number, because the mean of its divisors is an integer number (1333449283124).

Almost surely, 2^{21200000121100} is an apocalyptic number.

21200000121100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21200000121100 is an abundant number, since it is smaller than the sum of its proper divisors (26804174071364).

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

21200000121100 is a wasteful number, since it uses less digits than its factorization.

21200000121100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9217391394 (or 9217391387 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21200000121100 its reverse (112100000212), we get a palindrome (21312100121312).

The spelling of 21200000121100 in words is "twenty-one trillion, two hundred billion, one hundred twenty-one thousand, one hundred".