660017887 has 4 divisors (see below), whose sum is σ = 660622840. Its totient is φ = 659412936.

The previous prime is 660017861. The next prime is 660017899. The reversal of 660017887 is 788710066.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 660017887 - 2²⁷ = 525800159 is a prime.

It is a super-2 number, since 2×660017887² = 871247222319889538, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660017087) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 300837 + ... + 303022.

It is an arithmetic number, because the mean of its divisors is an integer number (165155710).

Almost surely, 2^660017887 is an apocalyptic number.

660017887 is a deficient number, since it is larger than the sum of its proper divisors (604953).

660017887 is a wasteful number, since it uses less digits than its factorization.

660017887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 604952.

The product of its (nonzero) digits is 112896, while the sum is 43.

The square root of 660017887 is about 25690.8132802370. The cubic root of 660017887 is about 870.6666344369. Note that the first 4 decimals are identical.

The spelling of 660017887 in words is "six hundred sixty million, seventeen thousand, eight hundred eighty-seven".