865193370820 has 24 divisors (see below), whose sum is σ = 1816970390424. Its totient is φ = 346065098496.

The previous prime is 865193370809. The next prime is 865193370889. The reversal of 865193370820 is 28073391568.

It can be written as a sum of positive squares in 4 ways, for example, as 1962844416 + 863230526404 = 44304^2 + 929102^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 175359 + ... + 1327078.

It is an arithmetic number, because the mean of its divisors is an integer number (75707099601).

Almost surely, 2^865193370820 is an apocalyptic number.

It is an amenable number.

865193370820 is an abundant number, since it is smaller than the sum of its proper divisors (951777019604).

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

865193370820 is a wasteful number, since it uses less digits than its factorization.

865193370820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1531239 (or 1531237 counting only the distinct ones).

The product of its (nonzero) digits is 2177280, while the sum is 52.

The spelling of 865193370820 in words is "eight hundred sixty-five billion, one hundred ninety-three million, three hundred seventy thousand, eight hundred twenty".