21100020022120 has 96 divisors (see below), whose sum is σ = 54431882786520. Its totient is φ = 7332495605760.

The previous prime is 21100020022061. The next prime is 21100020022121. The reversal of 21100020022120 is 2122002000112.

It is a happy number.

It can be written as a sum of positive squares in 12 ways, for example, as 5491699236 + 21094528322884 = 74106^2 + 4592878^2 .

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a self number, because there is not a number n which added to its sum of digits gives 21100020022120.

It is not an unprimeable number, because it can be changed into a prime (21100020022121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 91688161 + ... + 91918000.

Almost surely, 2^{21100020022120} is an apocalyptic number.

21100020022120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21100020022120 is an abundant number, since it is smaller than the sum of its proper divisors (33331862764400).

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

21100020022120 is a wasteful number, since it uses less digits than its factorization.

21100020022120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183606215 (or 183606198 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21100020022120 its reverse (2122002000112), we get a palindrome (23222022022232).

The spelling of 21100020022120 in words is "twenty-one trillion, one hundred billion, twenty million, twenty-two thousand, one hundred twenty".