1647045640 has 64 divisors (see below), whose sum is σ = 3874780800. Its totient is φ = 628902912.

The previous prime is 1647045623. The next prime is 1647045643. The reversal of 1647045640 is 465407461.

It is a self number, because there is not a number n which added to its sum of digits gives 1647045640.

It is not an unprimeable number, because it can be changed into a prime (1647045643) 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 15 ways as a sum of consecutive naturals, for example, 544051 + ... + 547069.

It is an arithmetic number, because the mean of its divisors is an integer number (60543450).

Almost surely, 2^1647045640 is an apocalyptic number.

1647045640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1647045640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1937390400).

1647045640 is an abundant number, since it is smaller than the sum of its proper divisors (2227735160).

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

1647045640 is a wasteful number, since it uses less digits than its factorization.

1647045640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3646 (or 3642 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 37.

The square root of 1647045640 is about 40583.8100724907. The cubic root of 1647045640 is about 1180.9600632532.

The spelling of 1647045640 in words is "one billion, six hundred forty-seven million, forty-five thousand, six hundred forty".