121243440100 has 72 divisors (see below), whose sum is σ = 266112920808. Its totient is φ = 47943168000.

The previous prime is 121243440083. The next prime is 121243440107. The reversal of 121243440100 is 1044342121.

It is a happy number.

It can be written as a sum of positive squares in 12 ways, for example, as 2131484224 + 119111955876 = 46168^2 + 345126^2 .

It is not an unprimeable number, because it can be changed into a prime (121243440107) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6788382 + ... + 6806218.

It is an arithmetic number, because the mean of its divisors is an integer number (3696012789).

Almost surely, 2^121243440100 is an apocalyptic number.

121243440100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121243440100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133056460404).

121243440100 is an abundant number, since it is smaller than the sum of its proper divisors (144869480708).

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

121243440100 is a wasteful number, since it uses less digits than its factorization.

121243440100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18625 (or 18618 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

Adding to 121243440100 its reverse (1044342121), we get a palindrome (122287782221).

The spelling of 121243440100 in words is "one hundred twenty-one billion, two hundred forty-three million, four hundred forty thousand, one hundred".