121009200 has 120 divisors (see below), whose sum is σ = 417504528. Its totient is φ = 29783040.

The previous prime is 121009183. The next prime is 121009201. The reversal of 121009200 is 2900121.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 121009200.

It is not an unprimeable number, because it can be changed into a prime (121009201) 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 23 ways as a sum of consecutive naturals, for example, 11722 + ... + 19478.

Almost surely, 2^121009200 is an apocalyptic number.

121009200 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 121009200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (208752264).

121009200 is an abundant number, since it is smaller than the sum of its proper divisors (296495328).

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

121009200 is a wasteful number, since it uses less digits than its factorization.

121009200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7791 (or 7780 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 15.

The square root of 121009200 is about 11000.4181738696. The cubic root of 121009200 is about 494.6212795456.

Adding to 121009200 its reverse (2900121), we get a palindrome (123909321).

It can be divided in two parts, 12 and 1009200, that multiplied together give a square (12110400 = 3480²).

The spelling of 121009200 in words is "one hundred twenty-one million, nine thousand, two hundred".