865663993 has 8 divisors (see below), whose sum is σ = 880358336. Its totient is φ = 850986000.

The previous prime is 865663943. The next prime is 865664017. The reversal of 865663993 is 399366568.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 865663993 - 2²¹ = 863566841 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (865663943) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 152830 + ... + 158392.

It is an arithmetic number, because the mean of its divisors is an integer number (110044792).

Almost surely, 2^865663993 is an apocalyptic number.

It is an amenable number.

865663993 is a deficient number, since it is larger than the sum of its proper divisors (14694343).

865663993 is a wasteful number, since it uses less digits than its factorization.

865663993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8175.

The product of its digits is 6298560, while the sum is 55.

The square root of 865663993 is about 29422.1683939169. The cubic root of 865663993 is about 953.0516798681.

The spelling of 865663993 in words is "eight hundred sixty-five million, six hundred sixty-three thousand, nine hundred ninety-three".