861709247 has 12 divisors (see below), whose sum is σ = 1005954696. Its totient is φ = 735986160.

The previous prime is 861709231. The next prime is 861709253. The reversal of 861709247 is 742907168.

It is not a de Polignac number, because 861709247 - 2⁴ = 861709231 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 861709198 and 861709207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861703247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17204 + ... + 44937.

It is an arithmetic number, because the mean of its divisors is an integer number (83829558).

Almost surely, 2^861709247 is an apocalyptic number.

861709247 is a deficient number, since it is larger than the sum of its proper divisors (144245449).

861709247 is a wasteful number, since it uses less digits than its factorization.

861709247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62438 (or 62431 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 44.

The square root of 861709247 is about 29354.8845509568. The cubic root of 861709247 is about 951.5981399343.

The spelling of 861709247 in words is "eight hundred sixty-one million, seven hundred nine thousand, two hundred forty-seven".