21100100202 has 24 divisors (see below), whose sum is σ = 46466343300. Its totient is φ = 6918065280.

The previous prime is 21100100179. The next prime is 21100100221. The reversal of 21100100202 is 20200100112.

It can be written as a sum of positive squares in 2 ways, for example, as 18401193801 + 2698906401 = 135651^2 + 51951^2 .

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 11 ways as a sum of consecutive naturals, for example, 9607327 + ... + 9609522.

Almost surely, 2^21100100202 is an apocalyptic number.

21100100202 is an abundant number, since it is smaller than the sum of its proper divisors (25366243098).

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

21100100202 is a wasteful number, since it uses less digits than its factorization.

21100100202 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19216918 (or 19216915 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 21100100202 its reverse (20200100112), we get a palindrome (41300200314).

The spelling of 21100100202 in words is "twenty-one billion, one hundred million, one hundred thousand, two hundred two".