321943813 has 4 divisors (see below), whose sum is σ = 322466220. Its totient is φ = 321421408.

The previous prime is 321943801. The next prime is 321943859. The reversal of 321943813 is 318349123.

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 129095044 + 192848769 = 11362^2 + 13887^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-321943813 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 (321943513) 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, 260278 + ... + 261511.

It is an arithmetic number, because the mean of its divisors is an integer number (80616555).

Almost surely, 2^321943813 is an apocalyptic number.

It is an amenable number.

321943813 is a deficient number, since it is larger than the sum of its proper divisors (522407).

321943813 is an equidigital number, since it uses as much as digits as its factorization.

321943813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 522406.

The product of its digits is 15552, while the sum is 34.

The square root of 321943813 is about 17942.7927870775. The cubic root of 321943813 is about 685.3725311287.

The spelling of 321943813 in words is "three hundred twenty-one million, nine hundred forty-three thousand, eight hundred thirteen".