661717116 has 18 divisors (see below), whose sum is σ = 1672673912. Its totient is φ = 220572360.

The previous prime is 661717033. The next prime is 661717141. The reversal of 661717116 is 611717166.

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 18381031 = 661717116 / (6 + 6 + 1 + 7 + 1 + 7 + 1 + 1 + 6).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9190480 + ... + 9190551.

Almost surely, 2^661717116 is an apocalyptic number.

It is an amenable number.

661717116 is an abundant number, since it is smaller than the sum of its proper divisors (1010956796).

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

661717116 is a wasteful number, since it uses less digits than its factorization.

661717116 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18381041 (or 18381036 counting only the distinct ones).

The product of its digits is 10584, while the sum is 36.

The square root of 661717116 is about 25723.8627736971. The cubic root of 661717116 is about 871.4131769180.

The spelling of 661717116 in words is "six hundred sixty-one million, seven hundred seventeen thousand, one hundred sixteen".