21222000020020 has 48 divisors (see below), whose sum is σ = 44713287234000. Its totient is φ = 8460804510720.

The previous prime is 21222000019991. The next prime is 21222000020029. The reversal of 21222000020020 is 2002000022212.

It can be written as a sum of positive squares in 8 ways, for example, as 5096522972304 + 16125477047716 = 2257548^2 + 4015654^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222000020029) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15458440 + ... + 16775200.

It is an arithmetic number, because the mean of its divisors is an integer number (931526817375).

Almost surely, 2^{21222000020020} is an apocalyptic number.

21222000020020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21222000020020 is an abundant number, since it is smaller than the sum of its proper divisors (23491287213980).

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

21222000020020 is a wasteful number, since it uses less digits than its factorization.

21222000020020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1319428 (or 1319426 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 13.

Adding to 21222000020020 its reverse (2002000022212), we get a palindrome (23224000042232).

The spelling of 21222000020020 in words is "twenty-one trillion, two hundred twenty-two billion, twenty thousand, twenty".