209999993 has 4 divisors (see below), whose sum is σ = 240000000. Its totient is φ = 179999988.

The previous prime is 209999987. The next prime is 210000017. The reversal of 209999993 is 399999902.

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 not a de Polignac number, because 209999993 - 2¹⁰ = 209998969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (209999893) 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, 14999993 + ... + 15000006.

It is an arithmetic number, because the mean of its divisors is an integer number (60000000).

Almost surely, 2^209999993 is an apocalyptic number.

It is an amenable number.

209999993 is a deficient number, since it is larger than the sum of its proper divisors (30000007).

209999993 is an equidigital number, since it uses as much as digits as its factorization.

209999993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30000006.

The product of its (nonzero) digits is 3188646, while the sum is 59.

The square root of 209999993 is about 14491.3765046665. The cubic root of 209999993 is about 594.3921886720.

The spelling of 209999993 in words is "two hundred nine million, nine hundred ninety-nine thousand, nine hundred ninety-three".