212221100161 has 4 divisors (see below), whose sum is σ = 242538400192. Its totient is φ = 181903800132.

The previous prime is 212221100071. The next prime is 212221100173. The reversal of 212221100161 is 161001122212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 212221100161 - 2¹³ = 212221091969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (212221103161) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15158650005 + ... + 15158650018.

It is an arithmetic number, because the mean of its divisors is an integer number (60634600048).

Almost surely, 2^212221100161 is an apocalyptic number.

It is an amenable number.

212221100161 is a deficient number, since it is larger than the sum of its proper divisors (30317300031).

212221100161 is an equidigital number, since it uses as much as digits as its factorization.

212221100161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30317300030.

The product of its (nonzero) digits is 96, while the sum is 19.

Adding to 212221100161 its reverse (161001122212), we get a palindrome (373222222373).

The spelling of 212221100161 in words is "two hundred twelve billion, two hundred twenty-one million, one hundred thousand, one hundred sixty-one".