209005939 has 4 divisors (see below), whose sum is σ = 221300424. Its totient is φ = 196711456.

The previous prime is 209005931. The next prime is 209006003. The reversal of 209005939 is 939500902.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 209005939 - 2³ = 209005931 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 209005898 and 209005907.

It is not an unprimeable number, because it can be changed into a prime (209005931) 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, 6147217 + ... + 6147250.

It is an arithmetic number, because the mean of its divisors is an integer number (55325106).

Almost surely, 2^209005939 is an apocalyptic number.

209005939 is a deficient number, since it is larger than the sum of its proper divisors (12294485).

209005939 is a wasteful number, since it uses less digits than its factorization.

209005939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12294484.

The product of its (nonzero) digits is 21870, while the sum is 37.

The square root of 209005939 is about 14457.0376979518. The cubic root of 209005939 is about 593.4528351718.

The spelling of 209005939 in words is "two hundred nine million, five thousand, nine hundred thirty-nine".