66515885 has 8 divisors (see below), whose sum is σ = 83289600. Its totient is φ = 50899024.

The previous prime is 66515881. The next prime is 66515887. The reversal of 66515885 is 58851566.

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 66515885 - 2² = 66515881 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66515881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 289085 + ... + 289314.

It is an arithmetic number, because the mean of its divisors is an integer number (10411200).

Almost surely, 2^66515885 is an apocalyptic number.

It is an amenable number.

66515885 is a deficient number, since it is larger than the sum of its proper divisors (16773715).

66515885 is a wasteful number, since it uses less digits than its factorization.

66515885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 578427.

The product of its digits is 288000, while the sum is 44.

The square root of 66515885 is about 8155.7271288341. The cubic root of 66515885 is about 405.1742074310.

The spelling of 66515885 in words is "sixty-six million, five hundred fifteen thousand, eight hundred eighty-five".