661317 has 8 divisors (see below), whose sum is σ = 933696. Its totient is φ = 414912.

The previous prime is 661267. The next prime is 661321. The reversal of 661317 is 713166.

661317 is digitally balanced in base 7, 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 not a de Polignac number, because 661317 - 2⁶ = 661253 is a prime.

661317 is strictly pandigital in base 7.

661317 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661327) 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, 6433 + ... + 6534.

It is an arithmetic number, because the mean of its divisors is an integer number (116712).

2⁶⁶¹³¹⁷ is an apocalyptic number.

It is an amenable number.

661317 is a deficient number, since it is larger than the sum of its proper divisors (272379).

661317 is a wasteful number, since it uses less digits than its factorization.

661317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12987.

The product of its digits is 756, while the sum is 24.

The square root of 661317 is about 813.2139939770. The cubic root of 661317 is about 87.1237504341.

The spelling of 661317 in words is "six hundred sixty-one thousand, three hundred seventeen".