21100222100 has 36 divisors (see below), whose sum is σ = 45839295264. Its totient is φ = 8430538080.

The previous prime is 21100222093. The next prime is 21100222109. The reversal of 21100222100 is 122200112.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21100222109) 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 11 ways as a sum of consecutive naturals, for example, 30242 + ... + 207641.

Almost surely, 2^21100222100 is an apocalyptic number.

21100222100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21100222100 is an abundant number, since it is smaller than the sum of its proper divisors (24739073164).

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

21100222100 is a wasteful number, since it uses less digits than its factorization.

21100222100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 238784 (or 238777 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21100222100 its reverse (122200112), we get a palindrome (21222422212).

The spelling of 21100222100 in words is "twenty-one billion, one hundred million, two hundred twenty-two thousand, one hundred".