668259481 has 4 divisors (see below), whose sum is σ = 675148852. Its totient is φ = 661370112.

The previous prime is 668259463. The next prime is 668259491. The reversal of 668259481 is 184952866.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 507375625 + 160883856 = 22525^2 + 12684^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-668259481 is a prime.

It is a super-2 number, since 2×668259481² = 893141467892778722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (668259461) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3444540 + ... + 3444733.

It is an arithmetic number, because the mean of its divisors is an integer number (168787213).

Almost surely, 2^668259481 is an apocalyptic number.

It is an amenable number.

668259481 is a deficient number, since it is larger than the sum of its proper divisors (6889371).

668259481 is an equidigital number, since it uses as much as digits as its factorization.

668259481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6889370.

The product of its digits is 829440, while the sum is 49.

The square root of 668259481 is about 25850.7152899103. The cubic root of 668259481 is about 874.2756371324.

The spelling of 668259481 in words is "six hundred sixty-eight million, two hundred fifty-nine thousand, four hundred eighty-one".