111221121210 has 32 divisors (see below), whose sum is σ = 266949231552. Its totient is φ = 29656905600.

The previous prime is 111221121203. The next prime is 111221121223. The reversal of 111221121210 is 12121122111.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 111221121210.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 338110 + ... + 580310.

It is an arithmetic number, because the mean of its divisors is an integer number (8342163486).

Almost surely, 2^111221121210 is an apocalyptic number.

111221121210 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

111221121210 is an abundant number, since it is smaller than the sum of its proper divisors (155728110342).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

111221121210 is a wasteful number, since it uses less digits than its factorization.

111221121210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 257518.

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

Adding to 111221121210 its reverse (12121122111), we get a palindrome (123342243321).

Subtracting from 111221121210 its reverse (12121122111), we obtain a palindrome (99099999099).

The spelling of 111221121210 in words is "one hundred eleven billion, two hundred twenty-one million, one hundred twenty-one thousand, two hundred ten".