66872309 has 8 divisors (see below), whose sum is σ = 77985600. Its totient is φ = 57318828.

The previous prime is 66872279. The next prime is 66872317. The reversal of 66872309 is 90327866.

It is a de Polignac number, because none of the positive numbers 2^k-66872309 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66872329) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 97139 + ... + 97824.

It is an arithmetic number, because the mean of its divisors is an integer number (9748200).

Almost surely, 2^66872309 is an apocalyptic number.

It is an amenable number.

66872309 is a deficient number, since it is larger than the sum of its proper divisors (11113291).

66872309 is an equidigital number, since it uses as much as digits as its factorization.

66872309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 194984 (or 194970 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 41.

The square root of 66872309 is about 8177.5490827020. The cubic root of 66872309 is about 405.8966244933.

The spelling of 66872309 in words is "sixty-six million, eight hundred seventy-two thousand, three hundred nine".