6557297666 has 8 divisors (see below), whose sum is σ = 9836310540. Its totient is φ = 3278527488.

The previous prime is 6557297633. The next prime is 6557297693. The reversal of 6557297666 is 6667927556.

It can be written as a sum of positive squares in 2 ways, for example, as 6283891441 + 273406225 = 79271^2 + 16535^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 40850 + ... + 121586.

Almost surely, 2^6557297666 is an apocalyptic number.

6557297666 is a deficient number, since it is larger than the sum of its proper divisors (3279012874).

6557297666 is a wasteful number, since it uses less digits than its factorization.

6557297666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121348.

The product of its digits is 28576800, while the sum is 59.

The square root of 6557297666 is about 80977.1428614273. The cubic root of 6557297666 is about 1871.7232407426.

The spelling of 6557297666 in words is "six billion, five hundred fifty-seven million, two hundred ninety-seven thousand, six hundred sixty-six".