21211202001221 has 8 divisors (see below), whose sum is σ = 21215129174304. Its totient is φ = 21207275102160.

The previous prime is 21211202001203. The next prime is 21211202001247. The reversal of 21211202001221 is 12210020211212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21211202001221 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21211202001221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211202001271) 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, 212514890 + ... + 212614676.

It is an arithmetic number, because the mean of its divisors is an integer number (2651891146788).

Almost surely, 2^{21211202001221} is an apocalyptic number.

It is an amenable number.

21211202001221 is a deficient number, since it is larger than the sum of its proper divisors (3927173083).

21211202001221 is an equidigital number, since it uses as much as digits as its factorization.

21211202001221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137011.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21211202001221 its reverse (12210020211212), we get a palindrome (33421222212433).

The spelling of 21211202001221 in words is "twenty-one trillion, two hundred eleven billion, two hundred two million, one thousand, two hundred twenty-one".