111221100121 has 4 divisors (see below), whose sum is σ = 115056310500. Its totient is φ = 107385889744.

The previous prime is 111221100083. The next prime is 111221100139. The reversal of 111221100121 is 121001122111.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 121001122111 = 2141 ⋅56516171.

It can be written as a sum of positive squares in 2 ways, for example, as 47143265625 + 64077834496 = 217125^2 + 253136^2 .

It is a cyclic number.

It is not a de Polignac number, because 111221100121 - 2⁷ = 111221099993 is a prime.

It is a super-2 number, since 2×111221100121² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (111221107121) 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, 1917605146 + ... + 1917605203.

It is an arithmetic number, because the mean of its divisors is an integer number (28764077625).

Almost surely, 2^111221100121 is an apocalyptic number.

It is an amenable number.

111221100121 is a deficient number, since it is larger than the sum of its proper divisors (3835210379).

111221100121 is an equidigital number, since it uses as much as digits as its factorization.

111221100121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3835210378.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 111221100121 its reverse (121001122111), we get a palindrome (232222222232).

The spelling of 111221100121 in words is "one hundred eleven billion, two hundred twenty-one million, one hundred thousand, one hundred twenty-one".