661575168 has 80 divisors (see below), whose sum is σ = 1958349360. Its totient is φ = 220520448.

The previous prime is 661575163. The next prime is 661575169. The reversal of 661575168 is 861575166.

661575168 is a `hidden beast` number, since 6 + 61 + 575 + 16 + 8 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661575163) 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, 10105 + ... + 37752.

It is an arithmetic number, because the mean of its divisors is an integer number (24479367).

Almost surely, 2^661575168 is an apocalyptic number.

It is an amenable number.

661575168 is an abundant number, since it is smaller than the sum of its proper divisors (1296774192).

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

661575168 is an equidigital number, since it uses as much as digits as its factorization.

661575168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47884 (or 47862 counting only the distinct ones).

The product of its digits is 302400, while the sum is 45.

The square root of 661575168 is about 25721.1035533081. The cubic root of 661575168 is about 871.3508621712.

The spelling of 661575168 in words is "six hundred sixty-one million, five hundred seventy-five thousand, one hundred sixty-eight".