168773821 has 2 divisors, whose sum is σ = 168773822. Its totient is φ = 168773820.

The previous prime is 168773809. The next prime is 168773837. The reversal of 168773821 is 128377861.

168773821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 141848100 + 26925721 = 11910^2 + 5189^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-168773821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (168773861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84386910 + 84386911.

It is an arithmetic number, because the mean of its divisors is an integer number (84386911).

Almost surely, 2^168773821 is an apocalyptic number.

It is an amenable number.

168773821 is a deficient number, since it is larger than the sum of its proper divisors (1).

168773821 is an equidigital number, since it uses as much as digits as its factorization.

168773821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 112896, while the sum is 43.

The square root of 168773821 is about 12991.2978951296. The cubic root of 168773821 is about 552.6307257399.

The spelling of 168773821 in words is "one hundred sixty-eight million, seven hundred seventy-three thousand, eight hundred twenty-one".