212121102312021 has 16 divisors (see below), whose sum is σ = 323249098291200. Its totient is φ = 121205705068848.

The previous prime is 212121102312017. The next prime is 212121102312047. The reversal of 212121102312021 is 120213201121212.

212121102312021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 212121102312021 - 2² = 212121102312017 is a prime.

It is a super-3 number, since 3×212121102312021³ (a number of 44 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212121102312001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 264314601 + ... + 265115918.

It is an arithmetic number, because the mean of its divisors is an integer number (20203068643200).

Almost surely, 2^{212121102312021} is an apocalyptic number.

212121102312021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

212121102312021 is a deficient number, since it is larger than the sum of its proper divisors (111127995979179).

212121102312021 is a wasteful number, since it uses less digits than its factorization.

212121102312021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 529449608.

The product of its (nonzero) digits is 192, while the sum is 21.

Adding to 212121102312021 its reverse (120213201121212), we get a palindrome (332334303433233).

The spelling of 212121102312021 in words is "two hundred twelve trillion, one hundred twenty-one billion, one hundred two million, three hundred twelve thousand, twenty-one".