6665526640 has 20 divisors (see below), whose sum is σ = 15497349624. Its totient is φ = 2666210624.

The previous prime is 6665526619. The next prime is 6665526671. The reversal of 6665526640 is 466255666.

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 41659462 + ... + 41659621.

Almost surely, 2^6665526640 is an apocalyptic number.

It is an amenable number.

6665526640 is an abundant number, since it is smaller than the sum of its proper divisors (8831822984).

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

6665526640 is a wasteful number, since it uses less digits than its factorization.

6665526640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83319096 (or 83319090 counting only the distinct ones).

The product of its (nonzero) digits is 1555200, while the sum is 46.

The square root of 6665526640 is about 81642.6765852272. The cubic root of 6665526640 is about 1881.9647710296.

The spelling of 6665526640 in words is "six billion, six hundred sixty-five million, five hundred twenty-six thousand, six hundred forty".