212102122221 has 36 divisors (see below), whose sum is σ = 336949290496. Its totient is φ = 128472006960.

The previous prime is 212102122187. The next prime is 212102122241. The reversal of 212102122221 is 122221201212.

It is a happy number.

212102122221 is a `hidden beast` number, since 21 + 210 + 212 + 2 + 221 = 666.

It is not a de Polignac number, because 212102122221 - 2⁹ = 212102121709 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212102122194 and 212102122203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212102122241) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1846740 + ... + 1958226.

Almost surely, 2^212102122221 is an apocalyptic number.

It is an amenable number.

212102122221 is a deficient number, since it is larger than the sum of its proper divisors (124847168275).

212102122221 is a wasteful number, since it uses less digits than its factorization.

212102122221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113262 (or 113248 counting only the distinct ones).

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

Adding to 212102122221 its reverse (122221201212), we get a palindrome (334323323433).

The spelling of 212102122221 in words is "two hundred twelve billion, one hundred two million, one hundred twenty-two thousand, two hundred twenty-one".