861561245 has 8 divisors (see below), whose sum is σ = 1034067384. Its totient is φ = 689119744.

The previous prime is 861561229. The next prime is 861561271. The reversal of 861561245 is 542165168.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1136356 + 860424889 = 1066^2 + 29333^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 861561245 - 2⁴ = 861561229 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 861561199 and 861561208.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20897 + ... + 46473.

It is an arithmetic number, because the mean of its divisors is an integer number (129258423).

Almost surely, 2^861561245 is an apocalyptic number.

It is an amenable number.

861561245 is a deficient number, since it is larger than the sum of its proper divisors (172506139).

861561245 is a wasteful number, since it uses less digits than its factorization.

861561245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32319.

The product of its digits is 57600, while the sum is 38.

The square root of 861561245 is about 29352.3635334533. The cubic root of 861561245 is about 951.5436565563.

The spelling of 861561245 in words is "eight hundred sixty-one million, five hundred sixty-one thousand, two hundred forty-five".