204020657 has 2 divisors, whose sum is σ = 204020658. Its totient is φ = 204020656.

The previous prime is 204020639. The next prime is 204020659. The reversal of 204020657 is 756020402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 193321216 + 10699441 = 13904^2 + 3271^2 .

It is a cyclic number.

It is not a de Polignac number, because 204020657 - 2²⁶ = 136911793 is a prime.

Together with 204020659, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (204020659) 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, 102010328 + 102010329.

It is an arithmetic number, because the mean of its divisors is an integer number (102010329).

Almost surely, 2^204020657 is an apocalyptic number.

It is an amenable number.

204020657 is a deficient number, since it is larger than the sum of its proper divisors (1).

204020657 is an equidigital number, since it uses as much as digits as its factorization.

204020657 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3360, while the sum is 26.

The square root of 204020657 is about 14283.5799784228. The cubic root of 204020657 is about 588.6964007744.

The spelling of 204020657 in words is "two hundred four million, twenty thousand, six hundred fifty-seven".