213121421304423 has 4 divisors (see below), whose sum is σ = 284161895072568. Its totient is φ = 142080947536280.

The previous prime is 213121421304403. The next prime is 213121421304553. The reversal of 213121421304423 is 324403124121312.

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 213121421304423 - 2¹⁸ = 213121421042279 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213121421304403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35520236884068 + ... + 35520236884073.

It is an arithmetic number, because the mean of its divisors is an integer number (71040473768142).

Almost surely, 2^{213121421304423} is an apocalyptic number.

213121421304423 is a deficient number, since it is larger than the sum of its proper divisors (71040473768145).

213121421304423 is an equidigital number, since it uses as much as digits as its factorization.

213121421304423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71040473768144.

The product of its (nonzero) digits is 27648, while the sum is 33.

Adding to 213121421304423 its reverse (324403124121312), we get a palindrome (537524545425735).

The spelling of 213121421304423 in words is "two hundred thirteen trillion, one hundred twenty-one billion, four hundred twenty-one million, three hundred four thousand, four hundred twenty-three".