21000021120221 has 32 divisors (see below), whose sum is σ = 26123177808000. Its totient is φ = 16585423073280.

The previous prime is 21000021120161. The next prime is 21000021120229. The reversal of 21000021120221 is 12202112000012.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21000021120221 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21000021120196 and 21000021120205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000021120229) 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 31 ways as a sum of consecutive naturals, for example, 194934230 + ... + 195041928.

It is an arithmetic number, because the mean of its divisors is an integer number (816349306500).

Almost surely, 2^{21000021120221} is an apocalyptic number.

It is an amenable number.

21000021120221 is a deficient number, since it is larger than the sum of its proper divisors (5123156687779).

21000021120221 is a wasteful number, since it uses less digits than its factorization.

21000021120221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187949.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21000021120221 its reverse (12202112000012), we get a palindrome (33202133120233).

It can be divided in two parts, 2100002 and 1120221, that added together give a palindrome (3220223).

The spelling of 21000021120221 in words is "twenty-one trillion, twenty-one million, one hundred twenty thousand, two hundred twenty-one".