221311312121 has 8 divisors (see below), whose sum is σ = 226766811264. Its totient is φ = 215858558880.

The previous prime is 221311312063. The next prime is 221311312223. The reversal of 221311312121 is 121213113122.

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-221311312121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221311312093 and 221311312102.

It is not an unprimeable number, because it can be changed into a prime (221311312021) 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, 522821 + ... + 846146.

It is an arithmetic number, because the mean of its divisors is an integer number (28345851408).

Almost surely, 2^221311312121 is an apocalyptic number.

It is an amenable number.

221311312121 is a deficient number, since it is larger than the sum of its proper divisors (5455499143).

221311312121 is a wasteful number, since it uses less digits than its factorization.

221311312121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1372951.

The product of its digits is 144, while the sum is 20.

Adding to 221311312121 its reverse (121213113122), we get a palindrome (342524425243).

The spelling of 221311312121 in words is "two hundred twenty-one billion, three hundred eleven million, three hundred twelve thousand, one hundred twenty-one".