865463671809 has 45 divisors (see below), whose sum is σ = 1421221221651. Its totient is φ = 524467619280.

The previous prime is 865463671771. The next prime is 865463671829. The reversal of 865463671809 is 908176364568.

The square root of 865463671809 is 930303.

It is a perfect power (a square), and thus also a powerful number.

865463671809 is a `hidden beast` number, since 8 + 6 + 546 + 3 + 6 + 7 + 1 + 80 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 4598874225 + 860864797584 = 67815^2 + 927828^2 .

It is not a de Polignac number, because 865463671809 - 2⁹ = 865463671297 is a prime.

It is a super-2 number, since 2×865463671809² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (865463671829) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 92095299 + ... + 92104695.

Almost surely, 2^865463671809 is an apocalyptic number.

865463671809 is the 930303-rd square number.

865463671809 is the 465152-nd centered octagonal number.

It is an amenable number.

865463671809 is a deficient number, since it is larger than the sum of its proper divisors (555757549842).

865463671809 is an frugal number, since it uses more digits than its factorization.

865463671809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18828 (or 9411 counting only the distinct ones).

The product of its (nonzero) digits is 52254720, while the sum is 63.

The spelling of 865463671809 in words is "eight hundred sixty-five billion, four hundred sixty-three million, six hundred seventy-one thousand, eight hundred nine".