168335138 has 4 divisors (see below), whose sum is σ = 252502710. Its totient is φ = 84167568.

The previous prime is 168335129. The next prime is 168335147. The reversal of 168335138 is 831533861.

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

It is an interprime number because it is at equal distance from previous prime (168335129) and next prime (168335147).

It can be written as a sum of positive squares in only one way, i.e., 142396489 + 25938649 = 11933^2 + 5093^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42083783 + ... + 42083786.

Almost surely, 2^168335138 is an apocalyptic number.

168335138 is a deficient number, since it is larger than the sum of its proper divisors (84167572).

168335138 is an equidigital number, since it uses as much as digits as its factorization.

168335138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84167571.

The product of its digits is 51840, while the sum is 38.

The square root of 168335138 is about 12974.4031847326. The cubic root of 168335138 is about 552.1515043949.

Adding to 168335138 its reverse (831533861), we get a palindrome (999868999).

The spelling of 168335138 in words is "one hundred sixty-eight million, three hundred thirty-five thousand, one hundred thirty-eight".