212122021 has 4 divisors (see below), whose sum is σ = 214677792. Its totient is φ = 209566252.

The previous prime is 212122019. The next prime is 212122049. The reversal of 212122021 is 120221212.

It is a happy number.

212122021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 212122021 - 2¹ = 212122019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212121992 and 212122010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212122081) 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, 1277761 + ... + 1277926.

It is an arithmetic number, because the mean of its divisors is an integer number (53669448).

Almost surely, 2^212122021 is an apocalyptic number.

It is an amenable number.

212122021 is a deficient number, since it is larger than the sum of its proper divisors (2555771).

212122021 is an equidigital number, since it uses as much as digits as its factorization.

212122021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2555770.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 212122021 is about 14564.4093941361. The cubic root of 212122021 is about 596.3875729709.

Adding to 212122021 its reverse (120221212), we get a palindrome (332343233).

It can be divided in two parts, 2121 and 22021, that added together give a palindrome (24142).

The spelling of 212122021 in words is "two hundred twelve million, one hundred twenty-two thousand, twenty-one".