647081 has 2 divisors, whose sum is σ = 647082. Its totient is φ = 647080.

The previous prime is 647069. The next prime is 647099. The reversal of 647081 is 180746.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 502681 + 144400 = 709^2 + 380^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-647081 is a prime.

It is a super-2 number, since 2×647081² = 837427641122, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 647081.

It is not a weakly prime, because it can be changed into another prime (647011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323540 + 323541.

It is an arithmetic number, because the mean of its divisors is an integer number (323541).

2⁶⁴⁷⁰⁸¹ is an apocalyptic number.

It is an amenable number.

647081 is a deficient number, since it is larger than the sum of its proper divisors (1).

647081 is an equidigital number, since it uses as much as digits as its factorization.

647081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 647081 is about 804.4134509069. The cubic root of 647081 is about 86.4940466127.

The spelling of 647081 in words is "six hundred forty-seven thousand, eighty-one".