21012212220212 has 6 divisors (see below), whose sum is σ = 36771371385378. Its totient is φ = 10506106110104.

The previous prime is 21012212220157. The next prime is 21012212220229. The reversal of 21012212220212 is 21202221221012.

It can be written as a sum of positive squares in only one way, i.e., 20837800744336 + 174411475876 = 4564844^2 + 417626^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2626526527523 + ... + 2626526527530.

It is an arithmetic number, because the mean of its divisors is an integer number (6128561897563).

Almost surely, 2^{21012212220212} is an apocalyptic number.

It is an amenable number.

21012212220212 is a deficient number, since it is larger than the sum of its proper divisors (15759159165166).

21012212220212 is a wasteful number, since it uses less digits than its factorization.

21012212220212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5253053055057 (or 5253053055055 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 21012212220212 its reverse (21202221221012), we get a palindrome (42214433441224).

The spelling of 21012212220212 in words is "twenty-one trillion, twelve billion, two hundred twelve million, two hundred twenty thousand, two hundred twelve".