6645376566 has 40 divisors (see below), whose sum is σ = 15370918464. Its totient is φ = 2143668240.

The previous prime is 6645376553. The next prime is 6645376583. The reversal of 6645376566 is 6656735466.

6645376566 is a `hidden beast` number, since 6 + 6 + 4 + 5 + 3 + 76 + 566 = 666.

It is a super-2 number, since 2×6645376566² = 88322059407883904712, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 656605 + ... + 666648.

Almost surely, 2^6645376566 is an apocalyptic number.

6645376566 is an abundant number, since it is smaller than the sum of its proper divisors (8725541898).

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

6645376566 is a wasteful number, since it uses less digits than its factorization.

6645376566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1323298 (or 1323289 counting only the distinct ones).

The product of its digits is 16329600, while the sum is 54.

The square root of 6645376566 is about 81519.1791298220. The cubic root of 6645376566 is about 1880.0664460822.

The spelling of 6645376566 in words is "six billion, six hundred forty-five million, three hundred seventy-six thousand, five hundred sixty-six".