21000101021100 has 72 divisors (see below), whose sum is σ = 67511435883920. Its totient is φ = 5600026938240.

The previous prime is 21000101021027. The next prime is 21000101021101. The reversal of 21000101021100 is 112010100012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (21000101021101) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3888904897 + ... + 3888910296.

Almost surely, 2^{21000101021100} is an apocalyptic number.

21000101021100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21000101021100 is an abundant number, since it is smaller than the sum of its proper divisors (46511334862820).

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

21000101021100 is a wasteful number, since it uses less digits than its factorization.

21000101021100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7777815216 (or 7777815203 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 21000101021100 its reverse (112010100012), we get a palindrome (21112111121112).

The spelling of 21000101021100 in words is "twenty-one trillion, one hundred one million, twenty-one thousand, one hundred".