66126809 has 16 divisors (see below), whose sum is σ = 78140160. Its totient is φ = 54781440.

The previous prime is 66126803. The next prime is 66126811. The reversal of 66126809 is 90862166.

It is not a de Polignac number, because 66126809 - 2⁸ = 66126553 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66126803) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31412 + ... + 33450.

It is an arithmetic number, because the mean of its divisors is an integer number (4883760).

Almost surely, 2^66126809 is an apocalyptic number.

It is an amenable number.

66126809 is a deficient number, since it is larger than the sum of its proper divisors (12013351).

66126809 is a wasteful number, since it uses less digits than its factorization.

66126809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2200.

The product of its (nonzero) digits is 31104, while the sum is 38.

The square root of 66126809 is about 8131.8392138556. The cubic root of 66126809 is about 404.3826574902.

The spelling of 66126809 in words is "sixty-six million, one hundred twenty-six thousand, eight hundred nine".