660017661 has 8 divisors (see below), whose sum is σ = 882241824. Its totient is φ = 438902640.

The previous prime is 660017651. The next prime is 660017669. The reversal of 660017661 is 166710066.

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

It is not a de Polignac number, because 660017661 - 2¹⁷ = 659886589 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660017669) 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, 275895 + ... + 278276.

It is an arithmetic number, because the mean of its divisors is an integer number (110280228).

Almost surely, 2^660017661 is an apocalyptic number.

It is an amenable number.

660017661 is a deficient number, since it is larger than the sum of its proper divisors (222224163).

660017661 is a wasteful number, since it uses less digits than its factorization.

660017661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 554571.

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 660017661 is about 25690.8088817772. The cubic root of 660017661 is about 870.6665350605. Note that the first 3 decimals are identical.

The spelling of 660017661 in words is "six hundred sixty million, seventeen thousand, six hundred sixty-one".