1686752321 has 2 divisors, whose sum is σ = 1686752322.
Its totient is φ = 1686752320.
The previous prime is 1686752279. The next prime is 1686752323. The reversal of 1686752321 is 1232576861.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 1656897025 + 29855296 = 40705^2 + 5464^2
It is an emirp because it is prime and its reverse (1232576861) is a distict prime.
It is a cyclic number.
It is not a de Polignac number, because 1686752321 - 226 = 1619643457 is a prime.
Together with 1686752323, it forms a pair of twin primes.
It is a Chen prime.
It is not a weakly prime, because it can be changed into another prime (1686752323) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 843376160 + 843376161.
It is an arithmetic number, because the mean of its divisors is an integer number (843376161).
Almost surely, 21686752321 is an apocalyptic number.
It is an amenable number.
1686752321 is a deficient number, since it is larger than the sum of its proper divisors (1).
1686752321 is an equidigital number, since it uses as much as digits as its factorization.
1686752321 is an evil number, because the sum of its binary digits is even.
The product of its digits is 120960, while the sum is 41.
The square root of 1686752321 is about 41070.0903456518.
The cubic root of 1686752321 is about 1190.3749309373.
The spelling of 1686752321 in words is "one billion, six hundred eighty-six million, seven hundred fifty-two thousand, three hundred twenty-one".