865949889647 has 2 divisors, whose sum is σ = 865949889648. Its totient is φ = 865949889646.

The previous prime is 865949889589. The next prime is 865949889671. The reversal of 865949889647 is 746988949568.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 865949889647 - 2¹² = 865949885551 is a prime.

It is a super-2 number, since 2×865949889647² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (865949889247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 432974944823 + 432974944824.

It is an arithmetic number, because the mean of its divisors is an integer number (432974944824).

Almost surely, 2^865949889647 is an apocalyptic number.

865949889647 is a deficient number, since it is larger than the sum of its proper divisors (1).

865949889647 is an equidigital number, since it uses as much as digits as its factorization.

865949889647 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7524679680, while the sum is 83.

The spelling of 865949889647 in words is "eight hundred sixty-five billion, nine hundred forty-nine million, eight hundred eighty-nine thousand, six hundred forty-seven".