209041864 has 16 divisors (see below), whose sum is σ = 395423820. Its totient is φ = 103595520.

The previous prime is 209041849. The next prime is 209041879. The reversal of 209041864 is 468140902.

It is an interprime number because it is at equal distance from previous prime (209041849) and next prime (209041879).

It can be written as a sum of positive squares in 2 ways, for example, as 209033764 + 8100 = 14458^2 + 90^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 114717 + ... + 116524.

Almost surely, 2^209041864 is an apocalyptic number.

It is an amenable number.

209041864 is a deficient number, since it is larger than the sum of its proper divisors (186381956).

209041864 is a wasteful number, since it uses less digits than its factorization.

209041864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231360 (or 231356 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 209041864 is about 14458.2801190183. The cubic root of 209041864 is about 593.4868351174.

The spelling of 209041864 in words is "two hundred nine million, forty-one thousand, eight hundred sixty-four".