647778520 has 32 divisors (see below), whose sum is σ = 1481400720. Its totient is φ = 254862720.

The previous prime is 647778497. The next prime is 647778569. The reversal of 647778520 is 25877746.

It is a Smith number, since the sum of its digits (46) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 130302 + ... + 135181.

Almost surely, 2^647778520 is an apocalyptic number.

It is an amenable number.

647778520 is an abundant number, since it is smaller than the sum of its proper divisors (833622200).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

647778520 is a wasteful number, since it uses less digits than its factorization.

647778520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 265555 (or 265551 counting only the distinct ones).

The product of its (nonzero) digits is 658560, while the sum is 46.

The square root of 647778520 is about 25451.4934728790. The cubic root of 647778520 is about 865.2511416183.

The spelling of 647778520 in words is "six hundred forty-seven million, seven hundred seventy-eight thousand, five hundred twenty".