66649499 has 4 divisors (see below), whose sum is σ = 76170864. Its totient is φ = 57128136.

The previous prime is 66649489. The next prime is 66649529. The reversal of 66649499 is 99494666.

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: 99494666 = 2 ⋅49747333.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66649499 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66649499.

It is not an unprimeable number, because it can be changed into a prime (66649439) 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, 4760672 + ... + 4760685.

It is an arithmetic number, because the mean of its divisors is an integer number (19042716).

Almost surely, 2^66649499 is an apocalyptic number.

66649499 is a deficient number, since it is larger than the sum of its proper divisors (9521365).

66649499 is an equidigital number, since it uses as much as digits as its factorization.

66649499 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9521364.

The product of its digits is 2519424, while the sum is 53.

The square root of 66649499 is about 8163.9144410019. The cubic root of 66649499 is about 405.4453243113.

The spelling of 66649499 in words is "sixty-six million, six hundred forty-nine thousand, four hundred ninety-nine".