823978593 has 18 divisors (see below), whose sum is σ = 1264324854. Its totient is φ = 517004544.

The previous prime is 823978591. The next prime is 823978607. The reversal of 823978593 is 395879328.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 343842849 + 480135744 = 18543^2 + 21912^2 .

It is not a de Polignac number, because 823978593 - 2¹ = 823978591 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (823978591) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 155796 + ... + 160997.

Almost surely, 2^823978593 is an apocalyptic number.

It is an amenable number.

823978593 is a deficient number, since it is larger than the sum of its proper divisors (440346261).

823978593 is a wasteful number, since it uses less digits than its factorization.

823978593 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 316833 (or 316813 counting only the distinct ones).

The product of its digits is 3265920, while the sum is 54.

The square root of 823978593 is about 28705.0273123019. The cubic root of 823978593 is about 937.5015108242.

The spelling of 823978593 in words is "eight hundred twenty-three million, nine hundred seventy-eight thousand, five hundred ninety-three".