168196021 has 4 divisors (see below), whose sum is σ = 192224032. Its totient is φ = 144168012.

The previous prime is 168196003. The next prime is 168196073. The reversal of 168196021 is 120691861.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 120691861 = 313 ⋅385597.

It is a cyclic number.

It is not a de Polignac number, because 168196021 - 2¹¹ = 168193973 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (168196081) 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, 12013995 + ... + 12014008.

It is an arithmetic number, because the mean of its divisors is an integer number (48056008).

Almost surely, 2^168196021 is an apocalyptic number.

It is an amenable number.

168196021 is a deficient number, since it is larger than the sum of its proper divisors (24028011).

168196021 is an equidigital number, since it uses as much as digits as its factorization.

168196021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24028010.

The product of its (nonzero) digits is 5184, while the sum is 34.

The square root of 168196021 is about 12969.0408666177. The cubic root of 168196021 is about 551.9993578460. Note that the first 3 decimals are identical.

The spelling of 168196021 in words is "one hundred sixty-eight million, one hundred ninety-six thousand, twenty-one".