668455891565 has 16 divisors (see below), whose sum is σ = 1000079464320. Its totient is φ = 416699776320.

The previous prime is 668455891529. The next prime is 668455891567. The reversal of 668455891565 is 565198554866.

It is not a de Polignac number, because 668455891565 - 2⁶ = 668455891501 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 668455891495 and 668455891504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668455891567) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 868124150 + ... + 868124919.

It is an arithmetic number, because the mean of its divisors is an integer number (62504966520).

Almost surely, 2^668455891565 is an apocalyptic number.

It is an amenable number.

668455891565 is a deficient number, since it is larger than the sum of its proper divisors (331623572755).

668455891565 is a wasteful number, since it uses less digits than its factorization.

668455891565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1736249092.

The product of its digits is 311040000, while the sum is 68.

The spelling of 668455891565 in words is "six hundred sixty-eight billion, four hundred fifty-five million, eight hundred ninety-one thousand, five hundred sixty-five".