866493909 has 16 divisors (see below), whose sum is σ = 1284148800. Its totient is φ = 577458288.

The previous prime is 866493907. The next prime is 866493911. The reversal of 866493909 is 909394668.

It is a happy number.

866493909 is a `hidden beast` number, since 8 + 66 + 493 + 90 + 9 = 666.

It is an interprime number because it is at equal distance from previous prime (866493907) and next prime (866493911).

It is not a de Polignac number, because 866493909 - 2¹ = 866493907 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866493907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 140707 + ... + 146735.

It is an arithmetic number, because the mean of its divisors is an integer number (80259300).

Almost surely, 2^866493909 is an apocalyptic number.

It is an amenable number.

866493909 is a deficient number, since it is larger than the sum of its proper divisors (417654891).

866493909 is a wasteful number, since it uses less digits than its factorization.

866493909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11361 (or 11355 counting only the distinct ones).

The product of its (nonzero) digits is 2519424, while the sum is 54.

The square root of 866493909 is about 29436.2685984484. The cubic root of 866493909 is about 953.3561475813.

The spelling of 866493909 in words is "eight hundred sixty-six million, four hundred ninety-three thousand, nine hundred nine".