21000100202209 has 4 divisors (see below), whose sum is σ = 21006167845140. Its totient is φ = 20994032559280.

The previous prime is 21000100202173. The next prime is 21000100202297. The reversal of 21000100202209 is 90220200100012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2028003846400 + 18972096355809 = 1424080^2 + 4355697^2 .

It is a cyclic number.

It is not a de Polignac number, because 21000100202209 - 2¹¹ = 21000100200161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21000800202209) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3033816274 + ... + 3033823195.

It is an arithmetic number, because the mean of its divisors is an integer number (5251541961285).

Almost surely, 2^{21000100202209} is an apocalyptic number.

It is an amenable number.

21000100202209 is a deficient number, since it is larger than the sum of its proper divisors (6067642931).

21000100202209 is an equidigital number, since it uses as much as digits as its factorization.

21000100202209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6067642930.

The product of its (nonzero) digits is 144, while the sum is 19.

The spelling of 21000100202209 in words is "twenty-one trillion, one hundred million, two hundred two thousand, two hundred nine".