121312100 has 72 divisors (see below), whose sum is σ = 324020928. Its totient is φ = 38390400.

The previous prime is 121312069. The next prime is 121312109. The reversal of 121312100 is 1213121.

It is not an unprimeable number, because it can be changed into a prime (121312109) 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, 2435 + ... + 15765.

Almost surely, 2^121312100 is an apocalyptic number.

121312100 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 121312100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (162010464).

121312100 is an abundant number, since it is smaller than the sum of its proper divisors (202708828).

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

121312100 is a wasteful number, since it uses less digits than its factorization.

121312100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13365 (or 13358 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 121312100 is about 11014.1772275554. The cubic root of 121312100 is about 495.0336337382.

Adding to 121312100 its reverse (1213121), we get a palindrome (122525221).

Multiplying 121312100 by its reverse (1213121), we get a square (147166256064100 = 12131210²).

121312100 divided by its reverse (1213121) gives a square (100 = 10²).

The spelling of 121312100 in words is "one hundred twenty-one million, three hundred twelve thousand, one hundred".