861590645 has 6 divisors (see below), whose sum is σ = 1033987542. Its totient is φ = 689220008.

The previous prime is 861590627. The next prime is 861590647. The reversal of 861590645 is 546095168.

It can be written as a sum of positive squares in only one way, i.e., 689272516 + 172318129 = 26254^2 + 13127^2 .

It is not a de Polignac number, because 861590645 - 2⁶ = 861590581 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 861590596 and 861590605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861590647) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 59072 + ... + 72198.

It is an arithmetic number, because the mean of its divisors is an integer number (172331257).

Almost surely, 2^861590645 is an apocalyptic number.

It is an amenable number.

861590645 is a deficient number, since it is larger than the sum of its proper divisors (172396897).

861590645 is an frugal number, since it uses more digits than its factorization.

861590645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26259 (or 13132 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 44.

The square root of 861590645 is about 29352.8643406397. The cubic root of 861590645 is about 951.5544799561.

The spelling of 861590645 in words is "eight hundred sixty-one million, five hundred ninety thousand, six hundred forty-five".