865461640 has 16 divisors (see below), whose sum is σ = 1947288780. Its totient is φ = 346184640.

The previous prime is 865461637. The next prime is 865461673. The reversal of 865461640 is 46164568.

It is a happy number.

865461640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 804403044 + 61058596 = 28362^2 + 7814^2 .

It is a super-2 number, since 2×865461640² = 1498047700622979200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40), and also a Moran number because the ratio is a prime number: 21636541 = 865461640 / (8 + 6 + 5 + 4 + 6 + 1 + 6 + 4 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 865461593 and 865461602.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10818231 + ... + 10818310.

Almost surely, 2^865461640 is an apocalyptic number.

It is an amenable number.

865461640 is an abundant number, since it is smaller than the sum of its proper divisors (1081827140).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

865461640 is a wasteful number, since it uses less digits than its factorization.

865461640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21636552 (or 21636548 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 40.

The square root of 865461640 is about 29418.7294083208. The cubic root of 865461640 is about 952.9774139879.

The spelling of 865461640 in words is "eight hundred sixty-five million, four hundred sixty-one thousand, six hundred forty".