6640442040 has 64 divisors (see below), whose sum is σ = 20608279200. Its totient is φ = 1709722112.

The previous prime is 6640442023. The next prime is 6640442057. The reversal of 6640442040 is 402440466.

It is an interprime number because it is at equal distance from previous prime (6640442023) and next prime (6640442057).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 6640441989 and 6640442007.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 950607 + ... + 957566.

Almost surely, 2^6640442040 is an apocalyptic number.

6640442040 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

6640442040 is an abundant number, since it is smaller than the sum of its proper divisors (13967837160).

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

6640442040 is a wasteful number, since it uses less digits than its factorization.

6640442040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1908216 (or 1908212 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 30.

The square root of 6640442040 is about 81488.9074659858. The cubic root of 6640442040 is about 1879.6009829196.

The spelling of 6640442040 in words is "six billion, six hundred forty million, four hundred forty-two thousand, forty".