205696391 has 8 divisors (see below), whose sum is σ = 217739280. Its totient is φ = 193983552.

The previous prime is 205696373. The next prime is 205696399. The reversal of 205696391 is 193696502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 205696391 - 2¹⁰ = 205695367 is a prime.

It is a super-2 number, since 2×205696391² = 84622010540849762, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205696399) 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 in 7 ways as a sum of consecutive naturals, for example, 81230 + ... + 83723.

It is an arithmetic number, because the mean of its divisors is an integer number (27217410).

Almost surely, 2^205696391 is an apocalyptic number.

205696391 is a deficient number, since it is larger than the sum of its proper divisors (12042889).

205696391 is a wasteful number, since it uses less digits than its factorization.

205696391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165025.

The product of its (nonzero) digits is 87480, while the sum is 41.

The square root of 205696391 is about 14342.1194737737. The cubic root of 205696391 is about 590.3037706046.

The spelling of 205696391 in words is "two hundred five million, six hundred ninety-six thousand, three hundred ninety-one".