20121221160 has 96 divisors (see below), whose sum is σ = 68835780000.
Its totient is φ = 5083254144.
The previous prime is 20121221137. The next prime is 20121221161. The reversal of 20121221160 is 6112212102.
It is a Harshad number since it is a multiple of its sum of digits (18).
It is not an unprimeable number, because it can be changed into a prime (20121221161) 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, 1464010 + ... + 1477689.
It is an arithmetic number, because the mean of its divisors is an integer number (717039375).
Almost surely, 220121221160 is an apocalyptic number.
20121221160 is a gapful number since it is divisible by the number (20) formed by its first and last digit.
It is an amenable number.
20121221160 is an abundant number, since it is smaller than the sum of its proper divisors (48714558840).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
20121221160 is a wasteful number, since it uses less digits than its factorization.
20121221160 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 2941735 (or 2941728 counting only the distinct ones).
The product of its (nonzero) digits is 96, while the sum is 18.
Adding to 20121221160 its reverse (6112212102), we get a palindrome (26233433262).
The spelling of 20121221160 in words is "twenty billion, one hundred twenty-one million, two hundred twenty-one thousand, one hundred sixty".