861724161 has 6 divisors (see below), whose sum is σ = 1244712690. Its totient is φ = 574482768.

The previous prime is 861724159. The next prime is 861724163. The reversal of 861724161 is 161427168.

It is a happy number.

861724161 is a `hidden beast` number, since 8 + 617 + 24 + 16 + 1 = 666.

861724161 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (861724159) and next prime (861724163).

It can be written as a sum of positive squares in only one way, i.e., 765075600 + 96648561 = 27660^2 + 9831^2 .

It is not a de Polignac number, because 861724161 - 2¹ = 861724159 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (861724163) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 47873556 + ... + 47873573.

It is an arithmetic number, because the mean of its divisors is an integer number (207452115).

Almost surely, 2^861724161 is an apocalyptic number.

It is an amenable number.

861724161 is a deficient number, since it is larger than the sum of its proper divisors (382988529).

861724161 is a wasteful number, since it uses less digits than its factorization.

861724161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95747135 (or 95747132 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 861724161 is about 29355.1385791313. The cubic root of 861724161 is about 951.6036298189.

The spelling of 861724161 in words is "eight hundred sixty-one million, seven hundred twenty-four thousand, one hundred sixty-one".