661445171 has 8 divisors (see below), whose sum is σ = 684372864. Its totient is φ = 638616960.

The previous prime is 661445149. The next prime is 661445173. The reversal of 661445171 is 171544166.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661445171 is a prime.

It is not an unprimeable number, because it can be changed into a prime (661445173) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11216 + ... + 38061.

It is an arithmetic number, because the mean of its divisors is an integer number (85546608).

Almost surely, 2^661445171 is an apocalyptic number.

661445171 is a deficient number, since it is larger than the sum of its proper divisors (22927693).

661445171 is a wasteful number, since it uses less digits than its factorization.

661445171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49741.

The product of its digits is 20160, while the sum is 35.

The square root of 661445171 is about 25718.5763797299. The cubic root of 661445171 is about 871.2937860578.

The spelling of 661445171 in words is "six hundred sixty-one million, four hundred forty-five thousand, one hundred seventy-one".