865121039 has 2 divisors, whose sum is σ = 865121040. Its totient is φ = 865121038.

The previous prime is 865121027. The next prime is 865121063. The reversal of 865121039 is 930121568.

865121039 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 865121039 - 2²⁴ = 848343823 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 (865121239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 432560519 + 432560520.

It is an arithmetic number, because the mean of its divisors is an integer number (432560520).

Almost surely, 2^865121039 is an apocalyptic number.

865121039 is a deficient number, since it is larger than the sum of its proper divisors (1).

865121039 is an equidigital number, since it uses as much as digits as its factorization.

865121039 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960, while the sum is 35.

The square root of 865121039 is about 29412.9399924591. The cubic root of 865121039 is about 952.8523833551.

The spelling of 865121039 in words is "eight hundred sixty-five million, one hundred twenty-one thousand, thirty-nine".