167721317 has 2 divisors, whose sum is σ = 167721318. Its totient is φ = 167721316.

The previous prime is 167721293. The next prime is 167721319. The reversal of 167721317 is 713127761.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 156100036 + 11621281 = 12494^2 + 3409^2 .

It is an emirp because it is prime and its reverse (713127761) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-167721317 is a prime.

Together with 167721319, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (167721319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83860658 + 83860659.

It is an arithmetic number, because the mean of its divisors is an integer number (83860659).

Almost surely, 2^167721317 is an apocalyptic number.

It is an amenable number.

167721317 is a deficient number, since it is larger than the sum of its proper divisors (1).

167721317 is an equidigital number, since it uses as much as digits as its factorization.

167721317 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12348, while the sum is 35.

The square root of 167721317 is about 12950.7265047178. The cubic root of 167721317 is about 551.4795611505.

The spelling of 167721317 in words is "one hundred sixty-seven million, seven hundred twenty-one thousand, three hundred seventeen".