647789018677 has 2 divisors, whose sum is σ = 647789018678. Its totient is φ = 647789018676.

The previous prime is 647789018641. The next prime is 647789018693. The reversal of 647789018677 is 776810987746.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 543944600676 + 103844418001 = 737526^2 + 322249^2 .

It is a cyclic number.

It is not a de Polignac number, because 647789018677 - 2¹¹ = 647789016629 is a prime.

It is a super-2 number, since 2×647789018677² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (647789012677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323894509338 + 323894509339.

It is an arithmetic number, because the mean of its divisors is an integer number (323894509339).

Almost surely, 2^647789018677 is an apocalyptic number.

It is an amenable number.

647789018677 is a deficient number, since it is larger than the sum of its proper divisors (1).

647789018677 is an equidigital number, since it uses as much as digits as its factorization.

647789018677 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 199148544, while the sum is 70.

The spelling of 647789018677 in words is "six hundred forty-seven billion, seven hundred eighty-nine million, eighteen thousand, six hundred seventy-seven".