63705557917 has 6 divisors (see below), whose sum is σ = 63766875998. Its totient is φ = 63644255544.

The previous prime is 63705557897. The next prime is 63705557947. The reversal of 63705557917 is 71975550736.

It can be written as a sum of positive squares in only one way, i.e., 38286357561 + 25419200356 = 195669^2 + 159434^2 .

It is not a de Polignac number, because 63705557917 - 2¹⁹ = 63705033629 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 (63705557947) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8786988 + ... + 8794234.

Almost surely, 2^63705557917 is an apocalyptic number.

It is an amenable number.

63705557917 is a deficient number, since it is larger than the sum of its proper divisors (61318081).

63705557917 is an frugal number, since it uses more digits than its factorization.

63705557917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15707 (or 8460 counting only the distinct ones).

The product of its (nonzero) digits is 6945750, while the sum is 55.

The spelling of 63705557917 in words is "sixty-three billion, seven hundred five million, five hundred fifty-seven thousand, nine hundred seventeen".