66515017 has 4 divisors (see below), whose sum is σ = 66533140. Its totient is φ = 66496896.

The previous prime is 66514963. The next prime is 66515021. The reversal of 66515017 is 71051566.

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

It can be written as a sum of positive squares in 2 ways, for example, as 5112121 + 61402896 = 2261^2 + 7836^2 .

It is a cyclic number.

It is not a de Polignac number, because 66515017 - 2¹⁵ = 66482249 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66515017.

It is not an unprimeable number, because it can be changed into a prime (66515027) 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, 1392 + ... + 11617.

It is an arithmetic number, because the mean of its divisors is an integer number (16633285).

Almost surely, 2^66515017 is an apocalyptic number.

It is an amenable number.

66515017 is a deficient number, since it is larger than the sum of its proper divisors (18123).

66515017 is a wasteful number, since it uses less digits than its factorization.

66515017 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18122.

The product of its (nonzero) digits is 6300, while the sum is 31.

The square root of 66515017 is about 8155.6739145211. The cubic root of 66515017 is about 405.1724449811.

The spelling of 66515017 in words is "sixty-six million, five hundred fifteen thousand, seventeen".