661318 has 8 divisors (see below), whose sum is σ = 1133712. Its totient is φ = 283416.

The previous prime is 661267. The next prime is 661321. The reversal of 661318 is 813166.

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

It is a junction number, because it is equal to n+sod(n) for n = 661292 and 661301.

It is a congruent number.

It is an unprimeable number.

661318 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23605 + ... + 23632.

It is an arithmetic number, because the mean of its divisors is an integer number (141714).

2⁶⁶¹³¹⁸ is an apocalyptic number.

661318 is a deficient number, since it is larger than the sum of its proper divisors (472394).

661318 is a wasteful number, since it uses less digits than its factorization.

661318 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47246.

The product of its digits is 864, while the sum is 25.

The square root of 661318 is about 813.2146088211. The cubic root of 661318 is about 87.1237943483.

It can be divided in two parts, 661 and 318, that added together give a palindrome (979).

The spelling of 661318 in words is "six hundred sixty-one thousand, three hundred eighteen".