6645652040 has 64 divisors (see below), whose sum is σ = 15879196800. Its totient is φ = 2496033792.

The previous prime is 6645652031. The next prime is 6645652049. The reversal of 6645652040 is 402565466.

It is an interprime number because it is at equal distance from previous prime (6645652031) and next prime (6645652049).

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a junction number, because it is equal to n+sod(n) for n = 6645651985 and 6645652003.

It is not an unprimeable number, because it can be changed into a prime (6645652049) 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, 47189 + ... + 124571.

It is an arithmetic number, because the mean of its divisors is an integer number (248112450).

Almost surely, 2^6645652040 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6645652040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7939598400).

6645652040 is an abundant number, since it is smaller than the sum of its proper divisors (9233544760).

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

6645652040 is a wasteful number, since it uses less digits than its factorization.

6645652040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77526 (or 77522 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 38.

The square root of 6645652040 is about 81520.8687392376. The cubic root of 6645652040 is about 1880.0924241570.

The spelling of 6645652040 in words is "six billion, six hundred forty-five million, six hundred fifty-two thousand, forty".