21002122221000 has 256 divisors, whose sum is σ = 68315622186240. Its totient is φ = 5367104870400.

The previous prime is 21002122220971. The next prime is 21002122221029. The reversal of 21002122221000 is 12222120012.

It is an interprime number because it is at equal distance from previous prime (21002122220971) and next prime (21002122221029).

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5301084 + ... + 8372916.

It is an arithmetic number, because the mean of its divisors is an integer number (266857899165).

Almost surely, 2^{21002122221000} is an apocalyptic number.

21002122221000 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 21002122221000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34157811093120).

21002122221000 is an abundant number, since it is smaller than the sum of its proper divisors (47313499965240).

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

21002122221000 is a wasteful number, since it uses less digits than its factorization.

21002122221000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3071953 (or 3071939 counting only the distinct ones).

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

Adding to 21002122221000 its reverse (12222120012), we get a palindrome (21014344341012).

The spelling of 21002122221000 in words is "twenty-one trillion, two billion, one hundred twenty-two million, two hundred twenty-one thousand".