221221221221000 has 1536 divisors, whose sum is σ = 747366761456640. Its totient is φ = 59304960000000.

The previous prime is 221221221220969. The next prime is 221221221221003. The reversal of 221221221221000 is 122122122122.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (221221221221003) by changing a digit.

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 383 ways as a sum of consecutive naturals, for example, 22343316050 + ... + 22343325950.

It is an arithmetic number, because the mean of its divisors is an integer number (486566901990).

Almost surely, 2^{221221221221000} is an apocalyptic number.

221221221221000 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 221221221221000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (373683380728320).

221221221221000 is an abundant number, since it is smaller than the sum of its proper divisors (526145540235640).

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

221221221221000 is a wasteful number, since it uses less digits than its factorization.

221221221221000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10084 (or 10057 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 221221221221000 its reverse (122122122122), we get a palindrome (221343343343122).

The spelling of 221221221221000 in words is "two hundred twenty-one trillion, two hundred twenty-one billion, two hundred twenty-one million, two hundred twenty-one thousand".