321521423 has 4 divisors (see below), whose sum is σ = 326792328. Its totient is φ = 316250520.

The previous prime is 321521413. The next prime is 321521437. The reversal of 321521423 is 324125123.

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 321521423 - 2⁶ = 321521359 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 (321521413) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2635361 + ... + 2635482.

It is an arithmetic number, because the mean of its divisors is an integer number (81698082).

Almost surely, 2^321521423 is an apocalyptic number.

321521423 is a deficient number, since it is larger than the sum of its proper divisors (5270905).

321521423 is an equidigital number, since it uses as much as digits as its factorization.

321521423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5270904.

The product of its digits is 1440, while the sum is 23.

The square root of 321521423 is about 17931.0184596414. The cubic root of 321521423 is about 685.0726638955.

Adding to 321521423 its reverse (324125123), we get a palindrome (645646546).

The spelling of 321521423 in words is "three hundred twenty-one million, five hundred twenty-one thousand, four hundred twenty-three".