864864865 has 16 divisors (see below), whose sum is σ = 1083224016. Its totient is φ = 662272000.

The previous prime is 864864839. The next prime is 864864911. The reversal of 864864865 is 568468468.

It can be written as a sum of positive squares in 8 ways, for example, as 299186209 + 565678656 = 17297^2 + 23784^2 .

It is a de Polignac number, because none of the positive numbers 2^k-864864865 is a prime.

It is a super-2 number, since 2×864864865² = 1495982469422936450, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28936 + ... + 50665.

It is an arithmetic number, because the mean of its divisors is an integer number (67701501).

Almost surely, 2^864864865 is an apocalyptic number.

It is an amenable number.

864864865 is a deficient number, since it is larger than the sum of its proper divisors (218359151).

864864865 is a wasteful number, since it uses less digits than its factorization.

864864865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79700.

The product of its digits is 8847360, while the sum is 55.

The square root of 864864865 is about 29408.5848860499. The cubic root of 864864865 is about 952.7583232592.

The spelling of 864864865 in words is "eight hundred sixty-four million, eight hundred sixty-four thousand, eight hundred sixty-five".