647764988 has 12 divisors (see below), whose sum is σ = 1220787960. Its totient is φ = 298968432.

The previous prime is 647764981. The next prime is 647765009. The reversal of 647764988 is 889467746.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647764981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6228458 + ... + 6228561.

It is an arithmetic number, because the mean of its divisors is an integer number (101732330).

Almost surely, 2^647764988 is an apocalyptic number.

It is an amenable number.

647764988 is a deficient number, since it is larger than the sum of its proper divisors (573022972).

647764988 is a wasteful number, since it uses less digits than its factorization.

647764988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12457036 (or 12457034 counting only the distinct ones).

The product of its digits is 16257024, while the sum is 59.

The square root of 647764988 is about 25451.2276324738. The cubic root of 647764988 is about 865.2451165857.

The spelling of 647764988 in words is "six hundred forty-seven million, seven hundred sixty-four thousand, nine hundred eighty-eight".