647132440 has 32 divisors (see below), whose sum is σ = 1503020160. Its totient is φ = 250502400.

The previous prime is 647132389. The next prime is 647132441. The reversal of 647132440 is 44231746.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647132441) 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 7 ways as a sum of consecutive naturals, for example, 259701 + ... + 262180.

It is an arithmetic number, because the mean of its divisors is an integer number (46969380).

Almost surely, 2^647132440 is an apocalyptic number.

It is an amenable number.

647132440 is an abundant number, since it is smaller than the sum of its proper divisors (855887720).

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

647132440 is a wasteful number, since it uses less digits than its factorization.

647132440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 521923 (or 521919 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 31.

The square root of 647132440 is about 25438.7979275751. The cubic root of 647132440 is about 864.9633851320.

The spelling of 647132440 in words is "six hundred forty-seven million, one hundred thirty-two thousand, four hundred forty".