212111221021 has 12 divisors (see below), whose sum is σ = 246761554332. Its totient is φ = 181794932928.

The previous prime is 212111221001. The next prime is 212111221037. The reversal of 212111221021 is 120122111212.

It can be written as a sum of positive squares in 2 ways, for example, as 126999576900 + 85111644121 = 356370^2 + 291739^2 .

It is not a de Polignac number, because 212111221021 - 2²³ = 212102832413 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212111220986 and 212111221004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212111221001) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 461401 + ... + 798193.

It is an arithmetic number, because the mean of its divisors is an integer number (20563462861).

Almost surely, 2^212111221021 is an apocalyptic number.

It is an amenable number.

212111221021 is a deficient number, since it is larger than the sum of its proper divisors (34650333311).

212111221021 is a wasteful number, since it uses less digits than its factorization.

212111221021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 349660 (or 349653 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 212111221021 its reverse (120122111212), we get a palindrome (332233332233).

The spelling of 212111221021 in words is "two hundred twelve billion, one hundred eleven million, two hundred twenty-one thousand, twenty-one".