66728999 has 2 divisors, whose sum is σ = 66729000. Its totient is φ = 66728998.

The previous prime is 66728993. The next prime is 66729043. The reversal of 66728999 is 99982766.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66728999 - 2²⁰ = 65680423 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66728993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33364499 + 33364500.

It is an arithmetic number, because the mean of its divisors is an integer number (33364500).

Almost surely, 2^66728999 is an apocalyptic number.

66728999 is a deficient number, since it is larger than the sum of its proper divisors (1).

66728999 is an equidigital number, since it uses as much as digits as its factorization.

66728999 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2939328, while the sum is 56.

The square root of 66728999 is about 8168.7819777492. The cubic root of 66728999 is about 405.6064662872.

The spelling of 66728999 in words is "sixty-six million, seven hundred twenty-eight thousand, nine hundred ninety-nine".