21000200002121 has 4 divisors (see below), whose sum is σ = 21000330354432. Its totient is φ = 21000069649812.

The previous prime is 21000200002097. The next prime is 21000200002123. The reversal of 21000200002121 is 12120000200012.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21000200002121 is a prime.

It is a super-3 number, since 3×21000200002121³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21000200002123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64934201 + ... + 65256806.

It is an arithmetic number, because the mean of its divisors is an integer number (5250082588608).

Almost surely, 2^{21000200002121} is an apocalyptic number.

It is an amenable number.

21000200002121 is a deficient number, since it is larger than the sum of its proper divisors (130352311).

21000200002121 is a wasteful number, since it uses less digits than its factorization.

21000200002121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130352310.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21000200002121 its reverse (12120000200012), we get a palindrome (33120200202133).

The spelling of 21000200002121 in words is "twenty-one trillion, two hundred million, two thousand, one hundred twenty-one".