66124809 has 16 divisors (see below), whose sum is σ = 100611840. Its totient is φ = 42891120.

The previous prime is 66124783. The next prime is 66124811. The reversal of 66124809 is 90842166.

It is not a de Polignac number, because 66124809 - 2²³ = 57736201 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66124879) 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, 32097 + ... + 34094.

It is an arithmetic number, because the mean of its divisors is an integer number (6288240).

Almost surely, 2^66124809 is an apocalyptic number.

It is an amenable number.

66124809 is a deficient number, since it is larger than the sum of its proper divisors (34487031).

66124809 is a wasteful number, since it uses less digits than its factorization.

66124809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66237 (or 66231 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 66124809 is about 8131.7162395155. The cubic root of 66124809 is about 404.3785806088.

The spelling of 66124809 in words is "sixty-six million, one hundred twenty-four thousand, eight hundred nine".