205999993 has 4 divisors (see below), whose sum is σ = 206078800. Its totient is φ = 205921188.

The previous prime is 205999987. The next prime is 206000059. The reversal of 205999993 is 399999502.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 205999993 - 2⁹ = 205999481 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205999943) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35343 + ... + 40756.

It is an arithmetic number, because the mean of its divisors is an integer number (51519700).

Almost surely, 2^205999993 is an apocalyptic number.

It is an amenable number.

205999993 is a deficient number, since it is larger than the sum of its proper divisors (78807).

205999993 is an equidigital number, since it uses as much as digits as its factorization.

205999993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78806.

The product of its (nonzero) digits is 1771470, while the sum is 55.

The square root of 205999993 is about 14352.6998505508. The cubic root of 205999993 is about 590.5940516729.

The spelling of 205999993 in words is "two hundred five million, nine hundred ninety-nine thousand, nine hundred ninety-three".