221213213221 has 32 divisors (see below), whose sum is σ = 297173318400. Its totient is φ = 159028807680.

The previous prime is 221213213209. The next prime is 221213213231. The reversal of 221213213221 is 122312312122.

It is a cyclic number.

It is not a de Polignac number, because 221213213221 - 2¹⁵ = 221213180453 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221213213192 and 221213213201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221213213231) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1832395 + ... + 1949383.

It is an arithmetic number, because the mean of its divisors is an integer number (9286666200).

Almost surely, 2^221213213221 is an apocalyptic number.

It is an amenable number.

221213213221 is a deficient number, since it is larger than the sum of its proper divisors (75960105179).

221213213221 is a wasteful number, since it uses less digits than its factorization.

221213213221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118909.

The product of its digits is 576, while the sum is 22.

Adding to 221213213221 its reverse (122312312122), we get a palindrome (343525525343).

It can be divided in two parts, 221213 and 213221, that added together give a palindrome (434434).

The spelling of 221213213221 in words is "two hundred twenty-one billion, two hundred thirteen million, two hundred thirteen thousand, two hundred twenty-one".