647564643827 has 4 divisors (see below), whose sum is σ = 653976175056. Its totient is φ = 641153112600.

The previous prime is 647564643809. The next prime is 647564643851. The reversal of 647564643827 is 728346465746.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 647564643827 - 2¹² = 647564639731 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 647564643827.

It is not an unprimeable number, because it can be changed into a prime (647564673827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3205765463 + ... + 3205765664.

It is an arithmetic number, because the mean of its divisors is an integer number (163494043764).

Almost surely, 2^647564643827 is an apocalyptic number.

647564643827 is a deficient number, since it is larger than the sum of its proper divisors (6411531229).

647564643827 is a wasteful number, since it uses less digits than its factorization.

647564643827 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6411531228.

The product of its digits is 162570240, while the sum is 62.

The spelling of 647564643827 in words is "six hundred forty-seven billion, five hundred sixty-four million, six hundred forty-three thousand, eight hundred twenty-seven".