661881163 has 8 divisors (see below), whose sum is σ = 685646640. Its totient is φ = 638478720.

The previous prime is 661881161. The next prime is 661881167. The reversal of 661881163 is 361188166.

661881163 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 661881163 - 2¹ = 661881161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661881161) 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, 87045 + ... + 94342.

It is an arithmetic number, because the mean of its divisors is an integer number (85705830).

Almost surely, 2^661881163 is an apocalyptic number.

661881163 is a deficient number, since it is larger than the sum of its proper divisors (23765477).

661881163 is a wasteful number, since it uses less digits than its factorization.

661881163 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181517.

The product of its digits is 41472, while the sum is 40.

The square root of 661881163 is about 25727.0511913045. The cubic root of 661881163 is about 871.4851819598.

The spelling of 661881163 in words is "six hundred sixty-one million, eight hundred eighty-one thousand, one hundred sixty-three".