647789961317 has 8 divisors (see below), whose sum is σ = 674625051000. Its totient is φ = 621254705344.

The previous prime is 647789961311. The next prime is 647789961319. The reversal of 647789961317 is 713169987746.

It is a Cunningham number, because it is equal to 804854²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 75892536196 + 571897425121 = 275486^2 + 756239^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 647789961317 - 2⁸ = 647789961061 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647789961311) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 74954018 + ... + 74962659.

It is an arithmetic number, because the mean of its divisors is an integer number (84328131375).

Almost surely, 2^647789961317 is an apocalyptic number.

It is an amenable number.

647789961317 is a deficient number, since it is larger than the sum of its proper divisors (26835089683).

647789961317 is a wasteful number, since it uses less digits than its factorization.

647789961317 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149916855.

The product of its digits is 96018048, while the sum is 68.

The spelling of 647789961317 in words is "six hundred forty-seven billion, seven hundred eighty-nine million, nine hundred sixty-one thousand, three hundred seventeen".