66500015 has 16 divisors (see below), whose sum is σ = 84284928. Its totient is φ = 50266656.

The previous prime is 66500011. The next prime is 66500017. The reversal of 66500015 is 51000566.

It is a cyclic number.

It is not a de Polignac number, because 66500015 - 2² = 66500011 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66500011) 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 15 ways as a sum of consecutive naturals, for example, 6062 + ... + 13028.

It is an arithmetic number, because the mean of its divisors is an integer number (5267808).

Almost surely, 2^66500015 is an apocalyptic number.

66500015 is a deficient number, since it is larger than the sum of its proper divisors (17784913).

66500015 is a wasteful number, since it uses less digits than its factorization.

66500015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7078.

The product of its (nonzero) digits is 900, while the sum is 23.

The square root of 66500015 is about 8154.7541348590. The cubic root of 66500015 is about 405.1419814140.

The spelling of 66500015 in words is "sixty-six million, five hundred thousand, fifteen".