111223212121 has 4 divisors (see below), whose sum is σ = 127112242432. Its totient is φ = 95334181812.

The previous prime is 111223212097. The next prime is 111223212131. The reversal of 111223212121 is 121212322111.

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 an emirpimes, since its reverse is a distinct semiprime: 121212322111 = 4241 ⋅28581071.

It is a cyclic number.

It is not a de Polignac number, because 111223212121 - 2⁹ = 111223211609 is a prime.

It is a super-2 number, since 2×111223212121² (a number of 23 digits) contains 22 as substring.

111223212121 is a modest number, since divided by 212121 gives 111223 as remainder.

It is not an unprimeable number, because it can be changed into a prime (111223212131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7944515145 + ... + 7944515158.

It is an arithmetic number, because the mean of its divisors is an integer number (31778060608).

Almost surely, 2^111223212121 is an apocalyptic number.

It is an amenable number.

111223212121 is a deficient number, since it is larger than the sum of its proper divisors (15889030311).

111223212121 is an equidigital number, since it uses as much as digits as its factorization.

111223212121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15889030310.

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

Adding to 111223212121 its reverse (121212322111), we get a palindrome (232435534232).

The spelling of 111223212121 in words is "one hundred eleven billion, two hundred twenty-three million, two hundred twelve thousand, one hundred twenty-one".