212121022120021 has 24 divisors (see below), whose sum is σ = 252701705566464. Its totient is φ = 177441822633600.

The previous prime is 212121022119953. The next prime is 212121022120079. The reversal of 212121022120021 is 120021220121212.

It is not a de Polignac number, because 212121022120021 - 2¹⁹ = 212121021595733 is a prime.

It is a super-3 number, since 3×212121022120021³ (a number of 44 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212121022120081) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 39382245 + ... + 44443258.

It is an arithmetic number, because the mean of its divisors is an integer number (10529237731936).

Almost surely, 2^{212121022120021} is an apocalyptic number.

It is an amenable number.

212121022120021 is a deficient number, since it is larger than the sum of its proper divisors (40580683446443).

212121022120021 is a wasteful number, since it uses less digits than its factorization.

212121022120021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83826761 (or 83826754 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 212121022120021 its reverse (120021220121212), we get a palindrome (332142242241233).

The spelling of 212121022120021 in words is "two hundred twelve trillion, one hundred twenty-one billion, twenty-two million, one hundred twenty thousand, twenty-one".