647677 has 4 divisors (see below), whose sum is σ = 663516. Its totient is φ = 631840.

The previous prime is 647663. The next prime is 647687. The reversal of 647677 is 776746.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 776746 = 2 ⋅388373.

It can be written as a sum of positive squares in 2 ways, for example, as 219961 + 427716 = 469^2 + 654^2 .

It is a cyclic number.

It is not a de Polignac number, because 647677 - 2¹¹ = 645629 is a prime.

It is a Duffinian number.

647677 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647617) 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 in 3 ways as a sum of consecutive naturals, for example, 7858 + ... + 7939.

It is an arithmetic number, because the mean of its divisors is an integer number (165879).

2⁶⁴⁷⁶⁷⁷ is an apocalyptic number.

It is an amenable number.

647677 is a deficient number, since it is larger than the sum of its proper divisors (15839).

647677 is a wasteful number, since it uses less digits than its factorization.

647677 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15838.

The product of its digits is 49392, while the sum is 37.

The square root of 647677 is about 804.7838219050. The cubic root of 647677 is about 86.5205938470.

The spelling of 647677 in words is "six hundred forty-seven thousand, six hundred seventy-seven".