121221021111 has 16 divisors (see below), whose sum is σ = 166181180928. Its totient is φ = 78551985600.

The previous prime is 121221021001. The next prime is 121221021113. The reversal of 121221021111 is 111120122121.

It is a happy number.

It is not a de Polignac number, because 121221021111 - 2²² = 121216826807 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121221021113) 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, 1785001 + ... + 1851666.

It is an arithmetic number, because the mean of its divisors is an integer number (10386323808).

Almost surely, 2^121221021111 is an apocalyptic number.

121221021111 is a deficient number, since it is larger than the sum of its proper divisors (44960159817).

121221021111 is a wasteful number, since it uses less digits than its factorization.

121221021111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3636982.

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

Adding to 121221021111 its reverse (111120122121), we get a palindrome (232341143232).

It can be divided in two parts, 1212210 and 21111, that added together give a palindrome (1233321).

The spelling of 121221021111 in words is "one hundred twenty-one billion, two hundred twenty-one million, twenty-one thousand, one hundred eleven".