21000121201 has 4 divisors (see below), whose sum is σ = 21265945600. Its totient is φ = 20734296804.

The previous prime is 21000121187. The next prime is 21000121211. The reversal of 21000121201 is 10212100012.

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 not a de Polignac number, because 21000121201 - 2⁷ = 21000121073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21000121211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 132912081 + ... + 132912238.

It is an arithmetic number, because the mean of its divisors is an integer number (5316486400).

Almost surely, 2^21000121201 is an apocalyptic number.

It is an amenable number.

21000121201 is a deficient number, since it is larger than the sum of its proper divisors (265824399).

21000121201 is an equidigital number, since it uses as much as digits as its factorization.

21000121201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 265824398.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21000121201 its reverse (10212100012), we get a palindrome (31212221213).

The spelling of 21000121201 in words is "twenty-one billion, one hundred twenty-one thousand, two hundred one".