668461 has 4 divisors (see below), whose sum is σ = 677692. Its totient is φ = 659232.

The previous prime is 668417. The next prime is 668471. The reversal of 668461 is 164866.

668461 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 220900 + 447561 = 470^2 + 669^2 .

It is a cyclic number.

It is not a de Polignac number, because 668461 - 2⁹ = 667949 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668471) 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, 4506 + ... + 4651.

It is an arithmetic number, because the mean of its divisors is an integer number (169423).

2⁶⁶⁸⁴⁶¹ is an apocalyptic number.

It is an amenable number.

668461 is a deficient number, since it is larger than the sum of its proper divisors (9231).

668461 is an equidigital number, since it uses as much as digits as its factorization.

668461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9230.

The product of its digits is 6912, while the sum is 31.

The square root of 668461 is about 817.5946428396. The cubic root of 668461 is about 87.4363509908.

The spelling of 668461 in words is "six hundred sixty-eight thousand, four hundred sixty-one".