21002011100100 has 54 divisors (see below), whose sum is σ = 65829637017690. Its totient is φ = 5600536293120.

The previous prime is 21002011100071. The next prime is 21002011100113. The reversal of 21002011100100 is 100111020012.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 1966434071616 + 19035577028484 = 1402296^2 + 4362978^2 .

It is a super-2 number, since 2×21002011100100² (a number of 27 digits) contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 11667783045 + ... + 11667784844.

Almost surely, 2^{21002011100100} is an apocalyptic number.

21002011100100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21002011100100 is an abundant number, since it is smaller than the sum of its proper divisors (44827625917590).

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

21002011100100 is a wasteful number, since it uses less digits than its factorization.

21002011100100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23335567909 (or 23335567899 counting only the distinct ones).

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

Adding to 21002011100100 its reverse (100111020012), we get a palindrome (21102122120112).

The spelling of 21002011100100 in words is "twenty-one trillion, two billion, eleven million, one hundred thousand, one hundred".