66505199 has 4 divisors (see below), whose sum is σ = 68650560. Its totient is φ = 64359840.

The previous prime is 66505181. The next prime is 66505217. The reversal of 66505199 is 99150566.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99150566 = 2 ⋅49575283.

It is an interprime number because it is at equal distance from previous prime (66505181) and next prime (66505217).

It is a cyclic number.

It is not a de Polignac number, because 66505199 - 2⁸ = 66504943 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66505099) 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 3 ways as a sum of consecutive naturals, for example, 1072634 + ... + 1072695.

It is an arithmetic number, because the mean of its divisors is an integer number (17162640).

Almost surely, 2^66505199 is an apocalyptic number.

66505199 is a deficient number, since it is larger than the sum of its proper divisors (2145361).

66505199 is a wasteful number, since it uses less digits than its factorization.

66505199 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2145360.

The product of its (nonzero) digits is 72900, while the sum is 41.

The square root of 66505199 is about 8155.0719800625. The cubic root of 66505199 is about 405.1525087372.

The spelling of 66505199 in words is "sixty-six million, five hundred five thousand, one hundred ninety-nine".