647673640 has 32 divisors (see below), whose sum is σ = 1470645000. Its totient is φ = 256690944.

The previous prime is 647673581. The next prime is 647673673. The reversal of 647673640 is 46376746.

647673640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 647498916 + 174724 = 25446^2 + 418^2 .

It is a super-2 number, since 2×647673640² = 838962287901699200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 69915 + ... + 78634.

Almost surely, 2^647673640 is an apocalyptic number.

It is an amenable number.

647673640 is an abundant number, since it is smaller than the sum of its proper divisors (822971360).

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

647673640 is a wasteful number, since it uses less digits than its factorization.

647673640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148669 (or 148665 counting only the distinct ones).

The product of its (nonzero) digits is 508032, while the sum is 43.

The square root of 647673640 is about 25449.4329995778. The cubic root of 647673640 is about 865.2044423042.

The spelling of 647673640 in words is "six hundred forty-seven million, six hundred seventy-three thousand, six hundred forty".