121213112221 has 4 divisors (see below), whose sum is σ = 121213891552. Its totient is φ = 121212332892.

The previous prime is 121213112213. The next prime is 121213112231. The reversal of 121213112221 is 122211312121.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 121213112221 - 2³ = 121213112213 is a prime.

It is a super-4 number, since 4×121213112221⁴ (a number of 45 digits) contains 4444 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121213112231) 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, 67671 + ... + 496996.

It is an arithmetic number, because the mean of its divisors is an integer number (30303472888).

Almost surely, 2^121213112221 is an apocalyptic number.

It is an amenable number.

121213112221 is a deficient number, since it is larger than the sum of its proper divisors (779331).

121213112221 is an equidigital number, since it uses as much as digits as its factorization.

121213112221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 779330.

The product of its digits is 96, while the sum is 19.

Adding to 121213112221 its reverse (122211312121), we get a palindrome (243424424342).

The spelling of 121213112221 in words is "one hundred twenty-one billion, two hundred thirteen million, one hundred twelve thousand, two hundred twenty-one".