168721907 has 8 divisors (see below), whose sum is σ = 171481680. Its totient is φ = 165974400.

The previous prime is 168721901. The next prime is 168722003. The reversal of 168721907 is 709127861.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 168721907 - 2¹⁸ = 168459763 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (168721901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27032 + ... + 32682.

It is an arithmetic number, because the mean of its divisors is an integer number (21435210).

Almost surely, 2^168721907 is an apocalyptic number.

168721907 is a deficient number, since it is larger than the sum of its proper divisors (2759773).

168721907 is an equidigital number, since it uses as much as digits as its factorization.

168721907 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6133.

The product of its (nonzero) digits is 42336, while the sum is 41.

The square root of 168721907 is about 12989.2997116858. The cubic root of 168721907 is about 552.5740577618.

The spelling of 168721907 in words is "one hundred sixty-eight million, seven hundred twenty-one thousand, nine hundred seven".