111221121021 has 16 divisors (see below), whose sum is σ = 150052193280. Its totient is φ = 73273469360.

The previous prime is 111221121017. The next prime is 111221121041. The reversal of 111221121021 is 120121122111.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 111221121021 - 2² = 111221121017 is a prime.

It is a super-2 number, since 2×111221121021² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111221121041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 498135 + ... + 685988.

It is an arithmetic number, because the mean of its divisors is an integer number (9378262080).

Almost surely, 2^111221121021 is an apocalyptic number.

It is an amenable number.

111221121021 is a deficient number, since it is larger than the sum of its proper divisors (38831072259).

111221121021 is a wasteful number, since it uses less digits than its factorization.

111221121021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1184496.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 111221121021 its reverse (120121122111), we get a palindrome (231342243132).

The spelling of 111221121021 in words is "one hundred eleven billion, two hundred twenty-one million, one hundred twenty-one thousand, twenty-one".