42865209 has 6 divisors (see below), whose sum is σ = 61916426. Its totient is φ = 28576800.

The previous prime is 42865187. The next prime is 42865217. The reversal of 42865209 is 90256824.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 39879225 + 2985984 = 6315^2 + 1728^2 .

It is not a de Polignac number, because 42865209 - 2¹⁷ = 42734137 is a prime.

It is a super-2 number, since 2×42865209² = 3674852285227362, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42865259) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2381392 + ... + 2381409.

Almost surely, 2^42865209 is an apocalyptic number.

It is an amenable number.

42865209 is a deficient number, since it is larger than the sum of its proper divisors (19051217).

42865209 is a wasteful number, since it uses less digits than its factorization.

42865209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4762807 (or 4762804 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 42865209 is about 6547.1527399321. The cubic root of 42865209 is about 349.9733557949.

The spelling of 42865209 in words is "forty-two million, eight hundred sixty-five thousand, two hundred nine".