205317672521 has 8 divisors (see below), whose sum is σ = 230724876480. Its totient is φ = 181283830992.

The previous prime is 205317672517. The next prime is 205317672541. The reversal of 205317672521 is 125276713502.

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

It is a cyclic number.

It is not a de Polignac number, because 205317672521 - 2² = 205317672517 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205317672541) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 343340291 + ... + 343340888.

It is an arithmetic number, because the mean of its divisors is an integer number (28840609560).

Almost surely, 2^205317672521 is an apocalyptic number.

It is an amenable number.

205317672521 is a deficient number, since it is larger than the sum of its proper divisors (25407203959).

205317672521 is a wasteful number, since it uses less digits than its factorization.

205317672521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 686681215.

The product of its (nonzero) digits is 176400, while the sum is 41.

The spelling of 205317672521 in words is "two hundred five billion, three hundred seventeen million, six hundred seventy-two thousand, five hundred twenty-one".