661168 has 30 divisors (see below), whose sum is σ = 1354452. Its totient is φ = 312480.

The previous prime is 661139. The next prime is 661183. The reversal of 661168 is 861166.

It is an unprimeable number.

661168 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 5 ways as a sum of consecutive naturals, for example, 15355 + ... + 15397.

2⁶⁶¹¹⁶⁸ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (677226).

661168 is an abundant number, since it is smaller than the sum of its proper divisors (693284).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661168 is a wasteful number, since it uses less digits than its factorization.

661168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113 (or 76 counting only the distinct ones).

The product of its digits is 1728, while the sum is 28.

The square root of 661168 is about 813.1223770134. The cubic root of 661168 is about 87.1172067171.

The spelling of 661168 in words is "six hundred sixty-one thousand, one hundred sixty-eight".