865680149 has 2 divisors, whose sum is σ = 865680150. Its totient is φ = 865680148.

The previous prime is 865680143. The next prime is 865680173. The reversal of 865680149 is 941086568.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 802588900 + 63091249 = 28330^2 + 7943^2 .

It is a cyclic number.

It is not a de Polignac number, because 865680149 - 2²⁸ = 597244693 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (865680143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 432840074 + 432840075.

It is an arithmetic number, because the mean of its divisors is an integer number (432840075).

Almost surely, 2^865680149 is an apocalyptic number.

It is an amenable number.

865680149 is a deficient number, since it is larger than the sum of its proper divisors (1).

865680149 is an equidigital number, since it uses as much as digits as its factorization.

865680149 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 414720, while the sum is 47.

The square root of 865680149 is about 29422.4429475188. The cubic root of 865680149 is about 953.0576088072.

The spelling of 865680149 in words is "eight hundred sixty-five million, six hundred eighty thousand, one hundred forty-nine".