668541001 has 4 divisors (see below), whose sum is σ = 668637892. Its totient is φ = 668444112.

The previous prime is 668540987. The next prime is 668541037. The reversal of 668541001 is 100145866.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 100145866 = 2 ⋅50072933.

It can be written as a sum of positive squares in 2 ways, for example, as 500864400 + 167676601 = 22380^2 + 12949^2 .

It is a cyclic number.

It is not a de Polignac number, because 668541001 - 2⁵ = 668540969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (668541061) by changing a digit.

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, 37230 + ... + 52183.

It is an arithmetic number, because the mean of its divisors is an integer number (167159473).

It is a 6900-hyperperfect number.

Almost surely, 2^668541001 is an apocalyptic number.

It is an amenable number.

668541001 is a deficient number, since it is larger than the sum of its proper divisors (96891).

668541001 is an equidigital number, since it uses as much as digits as its factorization.

668541001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96890.

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 668541001 is about 25856.1598270122. The cubic root of 668541001 is about 874.3983896112.

Adding to 668541001 its reverse (100145866), we get a palindrome (768686867).

The spelling of 668541001 in words is "six hundred sixty-eight million, five hundred forty-one thousand, one".