2121221220000 has 240 divisors, whose sum is σ = 7029781399872. Its totient is φ = 559825920000.

The previous prime is 2121221219989. The next prime is 2121221220017. The reversal of 2121221220000 is 221221212.

It is a tau number, because it is divible by the number of its divisors (240).

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

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 5637765 + ... + 6002235.

Almost surely, 2^{2121221220000} is an apocalyptic number.

2121221220000 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 2121221220000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3514890699936).

2121221220000 is an abundant number, since it is smaller than the sum of its proper divisors (4908560179872).

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

2121221220000 is an equidigital number, since it uses as much as digits as its factorization.

2121221220000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 364601 (or 364578 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 2121221220000 its reverse (221221212), we get a palindrome (2121442441212).

The spelling of 2121221220000 in words is "two trillion, one hundred twenty-one billion, two hundred twenty-one million, two hundred twenty thousand".