20121135200 has 72 divisors (see below), whose sum is σ = 49479536232. Its totient is φ = 7989662720.

The previous prime is 20121135143. The next prime is 20121135253. The reversal of 20121135200 is 253112102.

It is a happy number.

It is a super-3 number, since 3×20121135200³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 17807 + ... + 201393.

It is an arithmetic number, because the mean of its divisors is an integer number (687215781).

Almost surely, 2^20121135200 is an apocalyptic number.

20121135200 is a gapful number since it is divisible by the number (20) 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 20121135200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24739768116).

20121135200 is an abundant number, since it is smaller than the sum of its proper divisors (29358401032).

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

20121135200 is a wasteful number, since it uses less digits than its factorization.

20121135200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183744 (or 183731 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 17.

Adding to 20121135200 its reverse (253112102), we get a palindrome (20374247302).

The spelling of 20121135200 in words is "twenty billion, one hundred twenty-one million, one hundred thirty-five thousand, two hundred".