121201100100 has 54 divisors (see below), whose sum is σ = 379898117690. Its totient is φ = 32320293120.

The previous prime is 121201100063. The next prime is 121201100101. The reversal of 121201100100 is 1001102121.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 33735403584 + 87465696516 = 183672^2 + 295746^2 .

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (121201100101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 67333045 + ... + 67334844.

Almost surely, 2^121201100100 is an apocalyptic number.

121201100100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121201100100 is an abundant number, since it is smaller than the sum of its proper divisors (258697017590).

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

121201100100 is a wasteful number, since it uses less digits than its factorization.

121201100100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134667909 (or 134667899 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 121201100100 its reverse (1001102121), we get a palindrome (122202202221).

The spelling of 121201100100 in words is "one hundred twenty-one billion, two hundred one million, one hundred thousand, one hundred".