205851491 has 8 divisors (see below), whose sum is σ = 217140480. Its totient is φ = 194608008.

The previous prime is 205851479. The next prime is 205851497. The reversal of 205851491 is 194158502.

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 205851491 - 2⁶ = 205851427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205851497) 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, 1871 + ... + 20376.

It is an arithmetic number, because the mean of its divisors is an integer number (27142560).

Almost surely, 2^205851491 is an apocalyptic number.

205851491 is a deficient number, since it is larger than the sum of its proper divisors (11288989).

205851491 is a wasteful number, since it uses less digits than its factorization.

205851491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22753.

The product of its (nonzero) digits is 14400, while the sum is 35.

The square root of 205851491 is about 14347.5256054833. The cubic root of 205851491 is about 590.4521010512.

The spelling of 205851491 in words is "two hundred five million, eight hundred fifty-one thousand, four hundred ninety-one".