647743640 has 32 divisors (see below), whose sum is σ = 1463978880. Its totient is φ = 257932032.

The previous prime is 647743627. The next prime is 647743697. The reversal of 647743640 is 46347746.

It is a Smith number, since the sum of its digits (41) coincides with the sum of the digits of its prime factors.

It is a congruent number.

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, 27389 + ... + 45228.

It is an arithmetic number, because the mean of its divisors is an integer number (45749340).

Almost surely, 2^647743640 is an apocalyptic number.

It is an amenable number.

647743640 is an abundant number, since it is smaller than the sum of its proper divisors (816235240).

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

647743640 is a wasteful number, since it uses less digits than its factorization.

647743640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72851 (or 72847 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 41.

The square root of 647743640 is about 25450.8082386395. The cubic root of 647743640 is about 865.2356113609.

The spelling of 647743640 in words is "six hundred forty-seven million, seven hundred forty-three thousand, six hundred forty".