647564198857 has 4 divisors (see below), whose sum is σ = 650251187476. Its totient is φ = 644877210240.

The previous prime is 647564198779. The next prime is 647564198867. The reversal of 647564198857 is 758891465746.

647564198857 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 466408409481 + 181155789376 = 682941^2 + 425624^2 .

It is a cyclic number.

It is not a de Polignac number, because 647564198857 - 2³⁹ = 97808384969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (647564198867) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1343493948 + ... + 1343494429.

It is an arithmetic number, because the mean of its divisors is an integer number (162562796869).

Almost surely, 2^647564198857 is an apocalyptic number.

It is an amenable number.

647564198857 is a deficient number, since it is larger than the sum of its proper divisors (2686988619).

647564198857 is a wasteful number, since it uses less digits than its factorization.

647564198857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2686988618.

The product of its digits is 406425600, while the sum is 70.

The spelling of 647564198857 in words is "six hundred forty-seven billion, five hundred sixty-four million, one hundred ninety-eight thousand, eight hundred fifty-seven".