6656666566 has 32 divisors (see below), whose sum is σ = 11052671616. Its totient is φ = 2981520000.

The previous prime is 6656666551. The next prime is 6656666573.

It is a happy number.

6656666566 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×6656666566² = 88622419541804464712, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 6656666566.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 727681 + ... + 736771.

It is an arithmetic number, because the mean of its divisors is an integer number (345395988).

Almost surely, 2^6656666566 is an apocalyptic number.

6656666566 is a deficient number, since it is larger than the sum of its proper divisors (4396005050).

6656666566 is a wasteful number, since it uses less digits than its factorization.

6656666566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9588.

The product of its digits is 41990400, while the sum is 58.

The square root of 6656666566 is about 81588.3972510798. The cubic root of 6656666566 is about 1881.1305413401.

The spelling of 6656666566 in words is "six billion, six hundred fifty-six million, six hundred sixty-six thousand, five hundred sixty-six".