212121022122021 has 4 divisors (see below), whose sum is σ = 282828029496032. Its totient is φ = 141414014748012.

The previous prime is 212121022121963. The next prime is 212121022122077. The reversal of 212121022122021 is 120221220121212.

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 not a de Polignac number, because 212121022122021 - 2⁹ = 212121022121509 is a prime.

It is a super-3 number, since 3×212121022122021³ (a number of 44 digits) contains 333 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212121022122421) 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, 35353503687001 + ... + 35353503687006.

It is an arithmetic number, because the mean of its divisors is an integer number (70707007374008).

Almost surely, 2^{212121022122021} is an apocalyptic number.

It is an amenable number.

212121022122021 is a deficient number, since it is larger than the sum of its proper divisors (70707007374011).

212121022122021 is an equidigital number, since it uses as much as digits as its factorization.

212121022122021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70707007374010.

The product of its (nonzero) digits is 256, while the sum is 21.

Adding to 212121022122021 its reverse (120221220121212), we get a palindrome (332342242243233).

The spelling of 212121022122021 in words is "two hundred twelve trillion, one hundred twenty-one billion, twenty-two million, one hundred twenty-two thousand, twenty-one".