21210221120100 has 72 divisors (see below), whose sum is σ = 61707290980608. Its totient is φ = 5624810006400.

The previous prime is 21210221120089. The next prime is 21210221120107. The reversal of 21210221120100 is 102112201212.

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 21210221120100.

It is not an unprimeable number, because it can be changed into a prime (21210221120107) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 195251604 + ... + 195360203.

It is an arithmetic number, because the mean of its divisors is an integer number (857045708064).

Almost surely, 2^{21210221120100} is an apocalyptic number.

21210221120100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21210221120100 is an abundant number, since it is smaller than the sum of its proper divisors (40497069860508).

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

21210221120100 is a wasteful number, since it uses less digits than its factorization.

21210221120100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390612005 (or 390611998 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21210221120100 its reverse (102112201212), we get a palindrome (21312333321312).

The spelling of 21210221120100 in words is "twenty-one trillion, two hundred ten billion, two hundred twenty-one million, one hundred twenty thousand, one hundred".