201864391 has 2 divisors, whose sum is σ = 201864392. Its totient is φ = 201864390.

The previous prime is 201864373. The next prime is 201864427. The reversal of 201864391 is 193468102.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 201864391 - 2¹³ = 201856199 is a prime.

It is equal to p_11176477 and since 201864391 and 11176477 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201864301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100932195 + 100932196.

It is an arithmetic number, because the mean of its divisors is an integer number (100932196).

Almost surely, 2^201864391 is an apocalyptic number.

201864391 is a deficient number, since it is larger than the sum of its proper divisors (1).

201864391 is an equidigital number, since it uses as much as digits as its factorization.

201864391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 201864391 is about 14207.8988946290. The cubic root of 201864391 is about 586.6151009616.

The spelling of 201864391 in words is "two hundred one million, eight hundred sixty-four thousand, three hundred ninety-one".