668665566801 has 32 divisors (see below), whose sum is σ = 991943884800. Its totient is φ = 445179747600.

The previous prime is 668665566787. The next prime is 668665566841. The reversal of 668665566801 is 108665566866.

668665566801 is a `hidden beast` number, since 6 + 6 + 8 + 6 + 65 + 566 + 8 + 0 + 1 = 666.

It is not a de Polignac number, because 668665566801 - 2²² = 668661372497 is a prime.

It is a super-2 number, since 2×668665566801² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (668665566841) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 93817900 + ... + 93825026.

It is an arithmetic number, because the mean of its divisors is an integer number (30998246400).

Almost surely, 2^668665566801 is an apocalyptic number.

It is an amenable number.

668665566801 is a deficient number, since it is larger than the sum of its proper divisors (323278317999).

668665566801 is a wasteful number, since it uses less digits than its factorization.

668665566801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11306 (or 11300 counting only the distinct ones).

The product of its (nonzero) digits is 74649600, while the sum is 63.

The spelling of 668665566801 in words is "six hundred sixty-eight billion, six hundred sixty-five million, five hundred sixty-six thousand, eight hundred one".