2543203221421 has 4 divisors (see below), whose sum is σ = 2543575422492. Its totient is φ = 2542831020352.

The previous prime is 2543203221397. The next prime is 2543203221463. The reversal of 2543203221421 is 1241223023452.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1190957516100 + 1352245705321 = 1091310^2 + 1162861^2 .

It is a cyclic number.

It is not a de Polignac number, because 2543203221421 - 2¹⁵ = 2543203188653 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 (2543203221491) 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, 186090286 + ... + 186103951.

It is an arithmetic number, because the mean of its divisors is an integer number (635893855623).

Almost surely, 2^{2543203221421} is an apocalyptic number.

It is an amenable number.

2543203221421 is a deficient number, since it is larger than the sum of its proper divisors (372201071).

2543203221421 is an equidigital number, since it uses as much as digits as its factorization.

2543203221421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 372201070.

The product of its (nonzero) digits is 23040, while the sum is 31.

Adding to 2543203221421 its reverse (1241223023452), we get a palindrome (3784426244873).

The spelling of 2543203221421 in words is "two trillion, five hundred forty-three billion, two hundred three million, two hundred twenty-one thousand, four hundred twenty-one".