21210000221221 has 8 divisors (see below), whose sum is σ = 24276783263040. Its totient is φ = 18152412931968.

The previous prime is 21210000221173. The next prime is 21210000221269. The reversal of 21210000221221 is 12212200001212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21210000221173) and next prime (21210000221269).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21210000221221 - 2¹¹ = 21210000219173 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21210000221195 and 21210000221204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210000221281) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2298933196 + ... + 2298942421.

It is an arithmetic number, because the mean of its divisors is an integer number (3034597907880).

Almost surely, 2^{21210000221221} is an apocalyptic number.

It is an amenable number.

21210000221221 is a deficient number, since it is larger than the sum of its proper divisors (3066783041819).

21210000221221 is an equidigital number, since it uses as much as digits as its factorization.

21210000221221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4597876283.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21210000221221 its reverse (12212200001212), we get a palindrome (33422200222433).

The spelling of 21210000221221 in words is "twenty-one trillion, two hundred ten billion, two hundred twenty-one thousand, two hundred twenty-one".