204195391 has 2 divisors, whose sum is σ = 204195392. Its totient is φ = 204195390.

The previous prime is 204195389. The next prime is 204195421. The reversal of 204195391 is 193591402.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 204195391 - 2¹ = 204195389 is a prime.

Together with 204195389, 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 (204195371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102097695 + 102097696.

It is an arithmetic number, because the mean of its divisors is an integer number (102097696).

Almost surely, 2^204195391 is an apocalyptic number.

204195391 is a deficient number, since it is larger than the sum of its proper divisors (1).

204195391 is an equidigital number, since it uses as much as digits as its factorization.

204195391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9720, while the sum is 34.

The square root of 204195391 is about 14289.6952731680. The cubic root of 204195391 is about 588.8644163175.

The spelling of 204195391 in words is "two hundred four million, one hundred ninety-five thousand, three hundred ninety-one".