212121441 has 18 divisors (see below), whose sum is σ = 356422482. Its totient is φ = 121212000.

The previous prime is 212121439. The next prime is 212121449. The reversal of 212121441 is 144121212.

212121441 is a `hidden beast` number, since 212 + 12 + 1 + 441 = 666.

212121441 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 201526416 + 10595025 = 14196^2 + 3255^2 .

It is not a de Polignac number, because 212121441 - 2¹ = 212121439 is a prime.

It is not an unprimeable number, because it can be changed into a prime (212121449) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 240060 + ... + 240941.

It is an arithmetic number, because the mean of its divisors is an integer number (19801249).

Almost surely, 2^212121441 is an apocalyptic number.

212121441 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

212121441 is a deficient number, since it is larger than the sum of its proper divisors (144301041).

212121441 is a wasteful number, since it uses less digits than its factorization.

212121441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 481021 (or 481011 counting only the distinct ones).

The product of its digits is 128, while the sum is 18.

The square root of 212121441 is about 14564.3894825701. The cubic root of 212121441 is about 596.3870294078.

Adding to 212121441 its reverse (144121212), we get a palindrome (356242653).

The spelling of 212121441 in words is "two hundred twelve million, one hundred twenty-one thousand, four hundred forty-one".