321813749 has 2 divisors, whose sum is σ = 321813750. Its totient is φ = 321813748.

The previous prime is 321813743. The next prime is 321813787. The reversal of 321813749 is 947318123.

It is an a-pointer prime, because the next prime (321813787) can be obtained adding 321813749 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 187416100 + 134397649 = 13690^2 + 11593^2 .

It is an emirp because it is prime and its reverse (947318123) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 321813749 - 2²⁸ = 53378293 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (321813743) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160906874 + 160906875.

It is an arithmetic number, because the mean of its divisors is an integer number (160906875).

Almost surely, 2^321813749 is an apocalyptic number.

It is an amenable number.

321813749 is a deficient number, since it is larger than the sum of its proper divisors (1).

321813749 is an equidigital number, since it uses as much as digits as its factorization.

321813749 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36288, while the sum is 38.

The square root of 321813749 is about 17939.1680130378. The cubic root of 321813749 is about 685.2802227855.

The spelling of 321813749 in words is "three hundred twenty-one million, eight hundred thirteen thousand, seven hundred forty-nine".