167868721 has 2 divisors, whose sum is σ = 167868722. Its totient is φ = 167868720.

The previous prime is 167868713. The next prime is 167868731. The reversal of 167868721 is 127868761.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 166126321 + 1742400 = 12889^2 + 1320^2 .

It is an emirp because it is prime and its reverse (127868761) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 167868721 - 2³ = 167868713 is a prime.

It is not a weakly prime, because it can be changed into another prime (167868731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83934360 + 83934361.

It is an arithmetic number, because the mean of its divisors is an integer number (83934361).

Almost surely, 2^167868721 is an apocalyptic number.

It is an amenable number.

167868721 is a deficient number, since it is larger than the sum of its proper divisors (1).

167868721 is an equidigital number, since it uses as much as digits as its factorization.

167868721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 225792, while the sum is 46.

The square root of 167868721 is about 12956.4162097395. The cubic root of 167868721 is about 551.6410721061.

The spelling of 167868721 in words is "one hundred sixty-seven million, eight hundred sixty-eight thousand, seven hundred twenty-one".