66606019 has 4 divisors (see below), whose sum is σ = 66628744. Its totient is φ = 66583296.

The previous prime is 66606013. The next prime is 66606047. The reversal of 66606019 is 91060666.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 91060666 = 2 ⋅45530333.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66606019 is a prime.

It is a super-2 number, since 2×66606019² = 8872723534056722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66606013) 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, 6177 + ... + 13090.

It is an arithmetic number, because the mean of its divisors is an integer number (16657186).

Almost surely, 2^66606019 is an apocalyptic number.

66606019 is a deficient number, since it is larger than the sum of its proper divisors (22725).

66606019 is a wasteful number, since it uses less digits than its factorization.

66606019 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22724.

The product of its (nonzero) digits is 11664, while the sum is 34.

The square root of 66606019 is about 8161.2510683105. The cubic root of 66606019 is about 405.3571386143.

The spelling of 66606019 in words is "sixty-six million, six hundred six thousand, nineteen".