21012122212 has 12 divisors (see below), whose sum is σ = 36831203836. Its totient is φ = 10488921120.

The previous prime is 21012122191. The next prime is 21012122227. The reversal of 21012122212 is 21222121012.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 8003807296 + 13008314916 = 89464^2 + 114054^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4282239 + ... + 4287142.

Almost surely, 2^21012122212 is an apocalyptic number.

It is an amenable number.

21012122212 is a deficient number, since it is larger than the sum of its proper divisors (15819081624).

21012122212 is a wasteful number, since it uses less digits than its factorization.

21012122212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8569998 (or 8569996 counting only the distinct ones).

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

Adding to 21012122212 its reverse (21222121012), we get a palindrome (42234243224).

The spelling of 21012122212 in words is "twenty-one billion, twelve million, one hundred twenty-two thousand, two hundred twelve".