121221111220110 has 256 divisors, whose sum is σ = 362185769088000. Its totient is φ = 28596806300160.

The previous prime is 121221111219977. The next prime is 121221111220129. The reversal of 121221111220110 is 11022111122121.

It is a happy number.

121221111220110 is a `hidden beast` number, since 1 + 2 + 1 + 221 + 111 + 220 + 110 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 32589696 + ... + 36118284.

It is an arithmetic number, because the mean of its divisors is an integer number (1414788160500).

Almost surely, 2^{121221111220110} is an apocalyptic number.

121221111220110 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 121221111220110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (181092884544000).

121221111220110 is an abundant number, since it is smaller than the sum of its proper divisors (240964657867890).

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

121221111220110 is a wasteful number, since it uses less digits than its factorization.

121221111220110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3528928 (or 3528922 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 121221111220110 its reverse (11022111122121), we get a palindrome (132243222342231).

The spelling of 121221111220110 in words is "one hundred twenty-one trillion, two hundred twenty-one billion, one hundred eleven million, two hundred twenty thousand, one hundred ten".