204168691 has 4 divisors (see below), whose sum is σ = 216178632. Its totient is φ = 192158752.

The previous prime is 204168673. The next prime is 204168709. The reversal of 204168691 is 196861402.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 196861402 = 2 ⋅98430701.

It is an interprime number because it is at equal distance from previous prime (204168673) and next prime (204168709).

It is not a de Polignac number, because 204168691 - 2⁵ = 204168659 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 204168691.

It is not an unprimeable number, because it can be changed into a prime (204168641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6004945 + ... + 6004978.

It is an arithmetic number, because the mean of its divisors is an integer number (54044658).

Almost surely, 2^204168691 is an apocalyptic number.

204168691 is a deficient number, since it is larger than the sum of its proper divisors (12009941).

204168691 is a wasteful number, since it uses less digits than its factorization.

204168691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12009940.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 204168691 is about 14288.7610029701. The cubic root of 204168691 is about 588.8387491282.

The spelling of 204168691 in words is "two hundred four million, one hundred sixty-eight thousand, six hundred ninety-one".