647131261617 has 12 divisors (see below), whose sum is σ = 989730165060. Its totient is φ = 406043144448.

The previous prime is 647131261591. The next prime is 647131261661. The reversal of 647131261617 is 716162131746.

It is a happy number.

647131261617 is a `hidden beast` number, since 6 + 4 + 7 + 1 + 3 + 1 + 26 + 1 + 617 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 579716254881 + 67415006736 = 761391^2 + 259644^2 .

It is not a de Polignac number, because 647131261617 - 2¹⁰ = 647131260593 is a prime.

It is not an unprimeable number, because it can be changed into a prime (647131261717) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2114807892 + ... + 2114808197.

It is an arithmetic number, because the mean of its divisors is an integer number (82477513755).

Almost surely, 2^647131261617 is an apocalyptic number.

It is an amenable number.

647131261617 is a deficient number, since it is larger than the sum of its proper divisors (342598903443).

647131261617 is a wasteful number, since it uses less digits than its factorization.

647131261617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4229616112 (or 4229616109 counting only the distinct ones).

The product of its digits is 254016, while the sum is 45.

The spelling of 647131261617 in words is "six hundred forty-seven billion, one hundred thirty-one million, two hundred sixty-one thousand, six hundred seventeen".