866642013 has 6 divisors (see below), whose sum is σ = 1251816254. Its totient is φ = 577761336.

The previous prime is 866641987. The next prime is 866642017. The reversal of 866642013 is 310246668.

It can be written as a sum of positive squares in only one way, i.e., 563255289 + 303386724 = 23733^2 + 17418^2 .

It is not a de Polignac number, because 866642013 - 2⁵ = 866641981 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866642017) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 48146770 + ... + 48146787.

Almost surely, 2^866642013 is an apocalyptic number.

It is an amenable number.

866642013 is a deficient number, since it is larger than the sum of its proper divisors (385174241).

866642013 is a wasteful number, since it uses less digits than its factorization.

866642013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96293563 (or 96293560 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 866642013 is about 29438.7841630730. The cubic root of 866642013 is about 953.4104614138.

The spelling of 866642013 in words is "eight hundred sixty-six million, six hundred forty-two thousand, thirteen".