121000111221 has 16 divisors (see below), whose sum is σ = 176031083520. Its totient is φ = 73320516720.

The previous prime is 121000111189. The next prime is 121000111229. The reversal of 121000111221 is 122111000121.

It is not a de Polignac number, because 121000111221 - 2⁵ = 121000111189 is a prime.

It is a super-2 number, since 2×121000111221² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 121000111197 and 121000111206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121000111229) 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, 129711 + ... + 508748.

It is an arithmetic number, because the mean of its divisors is an integer number (11001942720).

Almost surely, 2^121000111221 is an apocalyptic number.

121000111221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121000111221 is a deficient number, since it is larger than the sum of its proper divisors (55030972299).

121000111221 is a wasteful number, since it uses less digits than its factorization.

121000111221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 644216.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 121000111221 its reverse (122111000121), we get a palindrome (243111111342).

Subtracting 121000111221 from its reverse (122111000121), we obtain a square (1110888900 = 33330²).

It can be divided in two parts, 121000 and 111221, that added together give a triangular number (232221 = T₆₈₁).

The spelling of 121000111221 in words is "one hundred twenty-one billion, one hundred eleven thousand, two hundred twenty-one".