521312303 has 4 divisors (see below), whose sum is σ = 521662968. Its totient is φ = 520961640.

The previous prime is 521312257. The next prime is 521312321. The reversal of 521312303 is 303213125.

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 521312303 - 2¹⁴ = 521295919 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 (521312353) 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, 173093 + ... + 176078.

It is an arithmetic number, because the mean of its divisors is an integer number (130415742).

Almost surely, 2^521312303 is an apocalyptic number.

521312303 is a deficient number, since it is larger than the sum of its proper divisors (350665).

521312303 is a wasteful number, since it uses less digits than its factorization.

521312303 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 350664.

The product of its (nonzero) digits is 540, while the sum is 20.

The square root of 521312303 is about 22832.2645175637. The cubic root of 521312303 is about 804.8210463417.

Adding to 521312303 its reverse (303213125), we get a palindrome (824525428).

The spelling of 521312303 in words is "five hundred twenty-one million, three hundred twelve thousand, three hundred three".