865406961 has 6 divisors (see below), whose sum is σ = 1250032290. Its totient is φ = 576937968.

The previous prime is 865406959. The next prime is 865406989. The reversal of 865406961 is 169604568.

It can be written as a sum of positive squares in only one way, i.e., 657614736 + 207792225 = 25644^2 + 14415^2 .

It is not a de Polignac number, because 865406961 - 2¹ = 865406959 is a prime.

It is not an unprimeable number, because it can be changed into a prime (865402961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 48078156 + ... + 48078173.

It is an arithmetic number, because the mean of its divisors is an integer number (208338715).

Almost surely, 2^865406961 is an apocalyptic number.

It is an amenable number.

865406961 is a deficient number, since it is larger than the sum of its proper divisors (384625329).

865406961 is a wasteful number, since it uses less digits than its factorization.

865406961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96156335 (or 96156332 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 45.

The square root of 865406961 is about 29417.8000707055. The cubic root of 865406961 is about 952.9573441789.

The spelling of 865406961 in words is "eight hundred sixty-five million, four hundred six thousand, nine hundred sixty-one".