660408491 has 8 divisors (see below), whose sum is σ = 676129344. Its totient is φ = 644704200.

The previous prime is 660408487. The next prime is 660408493. The reversal of 660408491 is 194804066.

660408491 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 660408491 - 2² = 660408487 is a prime.

It is a super-2 number, since 2×660408491² = 872278749969794162, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (660408493) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 119900 + ... + 125286.

It is an arithmetic number, because the mean of its divisors is an integer number (84516168).

Almost surely, 2^660408491 is an apocalyptic number.

660408491 is a deficient number, since it is larger than the sum of its proper divisors (15720853).

660408491 is a wasteful number, since it uses less digits than its factorization.

660408491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8281.

The product of its (nonzero) digits is 41472, while the sum is 38.

The square root of 660408491 is about 25698.4141728629. The cubic root of 660408491 is about 870.8383564515.

The spelling of 660408491 in words is "six hundred sixty million, four hundred eight thousand, four hundred ninety-one".