523697821 has 2 divisors, whose sum is σ = 523697822. Its totient is φ = 523697820.

The previous prime is 523697809. The next prime is 523697897. The reversal of 523697821 is 128796325.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 403005625 + 120692196 = 20075^2 + 10986^2 .

It is a cyclic number.

It is not a de Polignac number, because 523697821 - 2⁹ = 523697309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (523697021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 261848910 + 261848911.

It is an arithmetic number, because the mean of its divisors is an integer number (261848911).

Almost surely, 2^523697821 is an apocalyptic number.

It is an amenable number.

523697821 is a deficient number, since it is larger than the sum of its proper divisors (1).

523697821 is an equidigital number, since it uses as much as digits as its factorization.

523697821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 181440, while the sum is 43.

The square root of 523697821 is about 22884.4449572193. Note that the first 3 decimals coincide. The cubic root of 523697821 is about 806.0467952848.

The spelling of 523697821 in words is "five hundred twenty-three million, six hundred ninety-seven thousand, eight hundred twenty-one".