21211222210000 has 50 divisors (see below), whose sum is σ = 51354490116842. Its totient is φ = 8484488880000.

The previous prime is 21211222209899. The next prime is 21211222210001. The reversal of 21211222210000 is 1222211212.

It is a happy number.

It can be written as a sum of positive squares in 5 ways, for example, as 13451788558224 + 7759433651776 = 3667668^2 + 2785576^2 .

It is a tau number, because it is divible by the number of its divisors (50).

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211222210001) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 1060551111 + ... + 1060571110.

Almost surely, 2^{21211222210000} is an apocalyptic number.

21211222210000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21211222210000 is an abundant number, since it is smaller than the sum of its proper divisors (30143267906842).

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

21211222210000 is an equidigital number, since it uses as much as digits as its factorization.

21211222210000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2121122249 (or 2121122228 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21211222210000 its reverse (1222211212), we get a palindrome (21212444421212).

The spelling of 21211222210000 in words is "twenty-one trillion, two hundred eleven billion, two hundred twenty-two million, two hundred ten thousand".