20212543 has 4 divisors (see below), whose sum is σ = 21767368. Its totient is φ = 18657720.

The previous prime is 20212531. The next prime is 20212547. The reversal of 20212543 is 34521202.

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

It is a cyclic number.

It is not a de Polignac number, because 20212543 - 2¹³ = 20204351 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20212543.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20212547) 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, 777393 + ... + 777418.

It is an arithmetic number, because the mean of its divisors is an integer number (5441842).

Almost surely, 2^20212543 is an apocalyptic number.

20212543 is a deficient number, since it is larger than the sum of its proper divisors (1554825).

20212543 is a wasteful number, since it uses less digits than its factorization.

20212543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1554824.

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 20212543 is about 4495.8361847381. The cubic root of 20212543 is about 272.3999262192.

Adding to 20212543 its reverse (34521202), we get a palindrome (54733745).

The spelling of 20212543 in words is "twenty million, two hundred twelve thousand, five hundred forty-three".