647641 has 2 divisors, whose sum is σ = 647642. Its totient is φ = 647640.

The previous prime is 647627. The next prime is 647651. The reversal of 647641 is 146746.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 646416 + 1225 = 804^2 + 35^2 .

It is a cyclic number.

It is not a de Polignac number, because 647641 - 2⁵ = 647609 is a prime.

It is not a weakly prime, because it can be changed into another prime (647651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323820 + 323821.

It is an arithmetic number, because the mean of its divisors is an integer number (323821).

2⁶⁴⁷⁶⁴¹ is an apocalyptic number.

It is an amenable number.

647641 is a deficient number, since it is larger than the sum of its proper divisors (1).

647641 is an equidigital number, since it uses as much as digits as its factorization.

647641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4032, while the sum is 28.

The square root of 647641 is about 804.7614553394. The cubic root of 647641 is about 86.5189907851.

The spelling of 647641 in words is "six hundred forty-seven thousand, six hundred forty-one".