66817313 has 6 divisors (see below), whose sum is σ = 68409234. Its totient is φ = 65261616.

The previous prime is 66817297. The next prime is 66817337. The reversal of 66817313 is 31371866.

It can be written as a sum of positive squares in only one way, i.e., 59243809 + 7573504 = 7697^2 + 2752^2 .

It is not a de Polignac number, because 66817313 - 2⁴ = 66817297 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66817343) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 16220 + ... + 19917.

It is an arithmetic number, because the mean of its divisors is an integer number (11401539).

Almost surely, 2^66817313 is an apocalyptic number.

It is an amenable number.

66817313 is a deficient number, since it is larger than the sum of its proper divisors (1591921).

66817313 is an equidigital number, since it uses as much as digits as its factorization.

66817313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36223 (or 36180 counting only the distinct ones).

The product of its digits is 18144, while the sum is 35.

The square root of 66817313 is about 8174.1857698489. The cubic root of 66817313 is about 405.7853237506.

The spelling of 66817313 in words is "sixty-six million, eight hundred seventeen thousand, three hundred thirteen".