1978313 has 2 divisors, whose sum is σ = 1978314. Its totient is φ = 1978312.

The previous prime is 1978297. The next prime is 1978343. The reversal of 1978313 is 3138791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1471369 + 506944 = 1213^2 + 712^2 .

It is an emirp because it is prime and its reverse (3138791) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1978313 - 2⁴ = 1978297 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1978313.

It is not a weakly prime, because it can be changed into another prime (1978343) 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 as a sum of consecutive naturals, namely, 989156 + 989157.

It is an arithmetic number, because the mean of its divisors is an integer number (989157).

2^1978313 is an apocalyptic number.

It is an amenable number.

1978313 is a deficient number, since it is larger than the sum of its proper divisors (1).

1978313 is an equidigital number, since it uses as much as digits as its factorization.

1978313 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4536, while the sum is 32.

The square root of 1978313 is about 1406.5251508594. The cubic root of 1978313 is about 125.5350505000.

The spelling of 1978313 in words is "one million, nine hundred seventy-eight thousand, three hundred thirteen".