668461285 has 4 divisors (see below), whose sum is σ = 802153548. Its totient is φ = 534769024.

The previous prime is 668461271. The next prime is 668461309. The reversal of 668461285 is 582164866.

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 401040676 + 267420609 = 20026^2 + 16353^2 .

It is a cyclic number.

It is not a de Polignac number, because 668461285 - 2¹¹ = 668459237 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66846124 + ... + 66846133.

It is an arithmetic number, because the mean of its divisors is an integer number (200538387).

Almost surely, 2^668461285 is an apocalyptic number.

It is an amenable number.

668461285 is a deficient number, since it is larger than the sum of its proper divisors (133692263).

668461285 is a wasteful number, since it uses less digits than its factorization.

668461285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133692262.

The product of its digits is 552960, while the sum is 46.

The square root of 668461285 is about 25854.6182528383. The cubic root of 668461285 is about 874.3636341698.

It can be divided in two parts, 668461 and 285, that added together give a triangular number (668746 = T₁₁₅₆).

The spelling of 668461285 in words is "six hundred sixty-eight million, four hundred sixty-one thousand, two hundred eighty-five".