21211221222000 has 160 divisors (see below), whose sum is σ = 75983308215360. Its totient is φ = 5656325644800.

The previous prime is 21211221221989. The next prime is 21211221222001. The reversal of 21211221222000 is 22212211212.

It is a happy number.

21211221222000 is a `hidden beast` number, since 21 + 211 + 2 + 212 + 220 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211221222001) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 196346197 + ... + 196454196.

It is an arithmetic number, because the mean of its divisors is an integer number (474895676346).

Almost surely, 2^{21211221222000} is an apocalyptic number.

21211221222000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21211221222000 is an abundant number, since it is smaller than the sum of its proper divisors (54772086993360).

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

21211221222000 is a wasteful number, since it uses less digits than its factorization.

21211221222000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 392800425 (or 392800403 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21211221222000 its reverse (22212211212), we get a palindrome (21233433433212).

The spelling of 21211221222000 in words is "twenty-one trillion, two hundred eleven billion, two hundred twenty-one million, two hundred twenty-two thousand".