861961247617 has 8 divisors (see below), whose sum is σ = 914896312200. Its totient is φ = 809274123264.

The previous prime is 861961247599. The next prime is 861961247629. The reversal of 861961247617 is 716742169168.

It can be written as a sum of positive squares in 4 ways, for example, as 657013998096 + 204947249521 = 810564^2 + 452711^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-861961247617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (861961247717) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 61977892 + ... + 61991797.

It is an arithmetic number, because the mean of its divisors is an integer number (114362039025).

Almost surely, 2^861961247617 is an apocalyptic number.

It is an amenable number.

861961247617 is a deficient number, since it is larger than the sum of its proper divisors (52935064583).

861961247617 is a wasteful number, since it uses less digits than its factorization.

861961247617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123970115.

The product of its digits is 6096384, while the sum is 58.

The spelling of 861961247617 in words is "eight hundred sixty-one billion, nine hundred sixty-one million, two hundred forty-seven thousand, six hundred seventeen".