391693 has 2 divisors, whose sum is σ = 391694. Its totient is φ = 391692.

The previous prime is 391691. The next prime is 391711. The reversal of 391693 is 396193.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 233289 + 158404 = 483^2 + 398^2 .

It is a cyclic number.

It is not a de Polignac number, because 391693 - 2¹ = 391691 is a prime.

Together with 391691, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (391691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195846 + 195847.

It is an arithmetic number, because the mean of its divisors is an integer number (195847).

2³⁹¹⁶⁹³ is an apocalyptic number.

It is an amenable number.

391693 is a deficient number, since it is larger than the sum of its proper divisors (1).

391693 is an equidigital number, since it uses as much as digits as its factorization.

391693 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4374, while the sum is 31.

The square root of 391693 is about 625.8538167975. The cubic root of 391693 is about 73.1670036520.

The spelling of 391693 in words is "three hundred ninety-one thousand, six hundred ninety-three".