212121543 has 4 divisors (see below), whose sum is σ = 282828728. Its totient is φ = 141414360.

The previous prime is 212121541. The next prime is 212121607. The reversal of 212121543 is 345121212.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 212121543 - 2¹ = 212121541 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212121541) 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, 35353588 + ... + 35353593.

It is an arithmetic number, because the mean of its divisors is an integer number (70707182).

Almost surely, 2^212121543 is an apocalyptic number.

212121543 is a deficient number, since it is larger than the sum of its proper divisors (70707185).

212121543 is an equidigital number, since it uses as much as digits as its factorization.

212121543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70707184.

The product of its digits is 480, while the sum is 21.

The square root of 212121543 is about 14564.3929842613. The cubic root of 212121543 is about 596.3871250000.

Adding to 212121543 its reverse (345121212), we get a palindrome (557242755).

The spelling of 212121543 in words is "two hundred twelve million, one hundred twenty-one thousand, five hundred forty-three".