861761 has 2 divisors, whose sum is σ = 861762. Its totient is φ = 861760.

The previous prime is 861743. The next prime is 861797. The reversal of 861761 is 167168.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 591361 + 270400 = 769^2 + 520^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-861761 is a prime.

It is a super-2 number, since 2×861761² = 1485264042242, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (861701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 430880 + 430881.

It is an arithmetic number, because the mean of its divisors is an integer number (430881).

2⁸⁶¹⁷⁶¹ is an apocalyptic number.

It is an amenable number.

861761 is a deficient number, since it is larger than the sum of its proper divisors (1).

861761 is an equidigital number, since it uses as much as digits as its factorization.

861761 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2016, while the sum is 29.

The square root of 861761 is about 928.3108315645. The cubic root of 861761 is about 95.1617190085.

The spelling of 861761 in words is "eight hundred sixty-one thousand, seven hundred sixty-one".