21222021012210 has 80 divisors (see below), whose sum is σ = 57064604345496. Its totient is φ = 5659111602432.

The previous prime is 21222021012173. The next prime is 21222021012217. The reversal of 21222021012210 is 1221012022212.

It is a happy number.

21222021012210 is a `hidden beast` number, since 2 + 12 + 220 + 210 + 1 + 221 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 11430572713569 + 9791448298641 = 3380913^2 + 3129129^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21222021012217) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 58278622 + ... + 58641638.

Almost surely, 2^{21222021012210} is an apocalyptic number.

21222021012210 is an abundant number, since it is smaller than the sum of its proper divisors (35842583333286).

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

21222021012210 is a wasteful number, since it uses less digits than its factorization.

21222021012210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 435209 (or 435200 counting only the distinct ones).

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

Adding to 21222021012210 its reverse (1221012022212), we get a palindrome (22443033034422).

The spelling of 21222021012210 in words is "twenty-one trillion, two hundred twenty-two billion, twenty-one million, twelve thousand, two hundred ten".