21011331122100 has 216 divisors, whose sum is σ = 71857517991168. Its totient is φ = 5092840742400.

The previous prime is 21011331122081. The next prime is 21011331122129. The reversal of 21011331122100 is 122113311012.

21011331122100 is a `hidden beast` number, since 21 + 0 + 113 + 311 + 221 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 62866632 + ... + 63199968.

Almost surely, 2^{21011331122100} is an apocalyptic number.

21011331122100 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 21011331122100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35928758995584).

21011331122100 is an abundant number, since it is smaller than the sum of its proper divisors (50846186869068).

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

21011331122100 is a wasteful number, since it uses less digits than its factorization.

21011331122100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 339735 (or 339725 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

Adding to 21011331122100 its reverse (122113311012), we get a palindrome (21133444433112).

The spelling of 21011331122100 in words is "twenty-one trillion, eleven billion, three hundred thirty-one million, one hundred twenty-two thousand, one hundred".