12001221000 has 192 divisors, whose sum is σ = 40636252800. Its totient is φ = 3194640000.

The previous prime is 12001220993. The next prime is 12001221013. The reversal of 12001221000 is 12210021.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 8270275 + ... + 8271725.

It is an arithmetic number, because the mean of its divisors is an integer number (211647150).

Almost surely, 2^12001221000 is an apocalyptic number.

12001221000 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 12001221000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20318126400).

12001221000 is an abundant number, since it is smaller than the sum of its proper divisors (28635031800).

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

12001221000 is a wasteful number, since it uses less digits than its factorization.

12001221000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2397 (or 2380 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 12001221000 its reverse (12210021), we get a palindrome (12013431021).

The spelling of 12001221000 in words is "twelve billion, one million, two hundred twenty-one thousand".