21212202112 has 32 divisors (see below), whose sum is σ = 42694365420. Its totient is φ = 10496753664.

The previous prime is 21212202101. The next prime is 21212202127. The reversal of 21212202112 is 21120221212.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20997169216 + 215032896 = 144904^2 + 14664^2 .

It is a tau number, because it is divible by the number of its divisors (32).

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 841813 + ... + 866644.

Almost surely, 2^21212202112 is an apocalyptic number.

It is an amenable number.

21212202112 is an abundant number, since it is smaller than the sum of its proper divisors (21482163308).

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

21212202112 is an equidigital number, since it uses as much as digits as its factorization.

21212202112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1708568 (or 1708556 counting only the distinct ones).

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

Adding to 21212202112 its reverse (21120221212), we get a palindrome (42332423324).

The spelling of 21212202112 in words is "twenty-one billion, two hundred twelve million, two hundred two thousand, one hundred twelve".