647663755 has 4 divisors (see below), whose sum is σ = 777196512. Its totient is φ = 518131000.

The previous prime is 647663747. The next prime is 647663759. The reversal of 647663755 is 557366746.

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

It is not a de Polignac number, because 647663755 - 2³ = 647663747 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 647663699 and 647663708.

It is not an unprimeable number, because it can be changed into a prime (647663759) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64766371 + ... + 64766380.

It is an arithmetic number, because the mean of its divisors is an integer number (194299128).

Almost surely, 2^647663755 is an apocalyptic number.

647663755 is a deficient number, since it is larger than the sum of its proper divisors (129532757).

647663755 is a wasteful number, since it uses less digits than its factorization.

647663755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129532756.

The product of its digits is 3175200, while the sum is 49.

The square root of 647663755 is about 25449.2387901878. The cubic root of 647663755 is about 865.2000406071.

The spelling of 647663755 in words is "six hundred forty-seven million, six hundred sixty-three thousand, seven hundred fifty-five".