111111121221 has 8 divisors (see below), whose sum is σ = 148439220960. Its totient is φ = 73928551152.

The previous prime is 111111121213. The next prime is 111111121241. The reversal of 111111121221 is 122121111111.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 111111121221 - 2³ = 111111121213 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 111111121221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111111121241) 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, 36380635 + ... + 36383688.

It is an arithmetic number, because the mean of its divisors is an integer number (18554902620).

Almost surely, 2^111111121221 is an apocalyptic number.

It is an amenable number.

111111121221 is a deficient number, since it is larger than the sum of its proper divisors (37328099739).

111111121221 is an equidigital number, since it uses as much as digits as its factorization.

111111121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72764835.

The product of its digits is 8, while the sum is 15.

Adding to 111111121221 its reverse (122121111111), we get a palindrome (233232232332).

The spelling of 111111121221 in words is "one hundred eleven billion, one hundred eleven million, one hundred twenty-one thousand, two hundred twenty-one".