221020001211221 has 4 divisors (see below), whose sum is σ = 221064498901152. Its totient is φ = 220975503521292.

The previous prime is 221020001211187. The next prime is 221020001211239. The reversal of 221020001211221 is 122112100020122.

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-221020001211221 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 221020001211221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221020001411221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22248837515 + ... + 22248847448.

It is an arithmetic number, because the mean of its divisors is an integer number (55266124725288).

Almost surely, 2^{221020001211221} is an apocalyptic number.

It is an amenable number.

221020001211221 is a deficient number, since it is larger than the sum of its proper divisors (44497689931).

221020001211221 is an equidigital number, since it uses as much as digits as its factorization.

221020001211221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44497689930.

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

Adding to 221020001211221 its reverse (122112100020122), we get a palindrome (343132101231343).

The spelling of 221020001211221 in words is "two hundred twenty-one trillion, twenty billion, one million, two hundred eleven thousand, two hundred twenty-one".