320657693 has 4 divisors (see below), whose sum is σ = 321815580. Its totient is φ = 319499808.

The previous prime is 320657681. The next prime is 320657713. The reversal of 320657693 is 396756023.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 396756023 = 71 ⋅5588113.

It can be written as a sum of positive squares in 2 ways, for example, as 108722329 + 211935364 = 10427^2 + 14558^2 .

It is a cyclic number.

It is not a de Polignac number, because 320657693 - 2⁴ = 320657677 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 320657693.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (320657633) 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, 578528 + ... + 579081.

It is an arithmetic number, because the mean of its divisors is an integer number (80453895).

Almost surely, 2^320657693 is an apocalyptic number.

It is an amenable number.

320657693 is a deficient number, since it is larger than the sum of its proper divisors (1157887).

320657693 is a wasteful number, since it uses less digits than its factorization.

320657693 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1157886.

The product of its (nonzero) digits is 204120, while the sum is 41.

The square root of 320657693 is about 17906.9174622546. The cubic root of 320657693 is about 684.4586576715.

The spelling of 320657693 in words is "three hundred twenty million, six hundred fifty-seven thousand, six hundred ninety-three".