2221121001000 has 256 divisors, whose sum is σ = 7588662681600. Its totient is φ = 536404128000.

The previous prime is 2221121000971. The next prime is 2221121001031. The reversal of 2221121001000 is 1001211222.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 8551041 + ... + 8806959.

It is an arithmetic number, because the mean of its divisors is an integer number (29643213600).

Almost surely, 2^{2221121001000} is an apocalyptic number.

2221121001000 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 2221121001000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3794331340800).

2221121001000 is an abundant number, since it is smaller than the sum of its proper divisors (5367541680600).

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

2221121001000 is a wasteful number, since it uses less digits than its factorization.

2221121001000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256217 (or 256203 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 2221121001000 its reverse (1001211222), we get a palindrome (2222122212222).

The spelling of 2221121001000 in words is "two trillion, two hundred twenty-one billion, one hundred twenty-one million, one thousand".