21000001221222 has 64 divisors (see below), whose sum is σ = 42859368699840. Its totient is φ = 6857705779200.

The previous prime is 21000001221209. The next prime is 21000001221233. The reversal of 21000001221222 is 22212210000012.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 370257138 + ... + 370313850.

It is an arithmetic number, because the mean of its divisors is an integer number (669677635935).

Almost surely, 2^{21000001221222} is an apocalyptic number.

21000001221222 is an abundant number, since it is smaller than the sum of its proper divisors (21859367478618).

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

21000001221222 is a wasteful number, since it uses less digits than its factorization.

21000001221222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60809.

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

Adding to 21000001221222 its reverse (22212210000012), we get a palindrome (43212211221234).

The spelling of 21000001221222 in words is "twenty-one trillion, one million, two hundred twenty-one thousand, two hundred twenty-two".