121221110100 has 72 divisors (see below), whose sum is σ = 355967959648. Its totient is φ = 31843152000.

The previous prime is 121221110039. The next prime is 121221110107. The reversal of 121221110100 is 1011122121.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121221110107) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 2995351 + ... + 3035550.

Almost surely, 2^121221110100 is an apocalyptic number.

121221110100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121221110100 is an abundant number, since it is smaller than the sum of its proper divisors (234746849548).

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

121221110100 is a wasteful number, since it uses less digits than its factorization.

121221110100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6030985 (or 6030978 counting only the distinct ones).

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

Adding to 121221110100 its reverse (1011122121), we get a palindrome (122232232221).

The spelling of 121221110100 in words is "one hundred twenty-one billion, two hundred twenty-one million, one hundred ten thousand, one hundred".