21204100201 has 6 divisors (see below), whose sum is σ = 21960489902. Its totient is φ = 20472923520.

The previous prime is 21204100189. The next prime is 21204100217. The reversal of 21204100201 is 10200140212.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 128029225 + 21076070976 = 11315^2 + 145176^2 .

It is not a de Polignac number, because 21204100201 - 2⁹ = 21204099689 is a prime.

It is a super-2 number, since 2×21204100201² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21204100231) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12605640 + ... + 12607321.

Almost surely, 2^21204100201 is an apocalyptic number.

It is an amenable number.

21204100201 is a deficient number, since it is larger than the sum of its proper divisors (756389701).

21204100201 is an equidigital number, since it uses as much as digits as its factorization.

21204100201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25213019 (or 25212990 counting only the distinct ones).

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

Adding to 21204100201 its reverse (10200140212), we get a palindrome (31404240413).

The spelling of 21204100201 in words is "twenty-one billion, two hundred four million, one hundred thousand, two hundred one".