168639397 has 4 divisors (see below), whose sum is σ = 170309196. Its totient is φ = 166969600.

The previous prime is 168639391. The next prime is 168639407. The reversal of 168639397 is 793936861.

168639397 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 158911236 + 9728161 = 12606^2 + 3119^2 .

It is a cyclic number.

It is not a de Polignac number, because 168639397 - 2³ = 168639389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (168639391) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 834748 + ... + 834949.

It is an arithmetic number, because the mean of its divisors is an integer number (42577299).

Almost surely, 2^168639397 is an apocalyptic number.

It is an amenable number.

168639397 is a deficient number, since it is larger than the sum of its proper divisors (1669799).

168639397 is a wasteful number, since it uses less digits than its factorization.

168639397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1669798.

The product of its digits is 1469664, while the sum is 52.

The square root of 168639397 is about 12986.1232475285. The cubic root of 168639397 is about 552.4839680585.

The spelling of 168639397 in words is "one hundred sixty-eight million, six hundred thirty-nine thousand, three hundred ninety-seven".