168853478821 has 2 divisors, whose sum is σ = 168853478822. Its totient is φ = 168853478820.

The previous prime is 168853478723. The next prime is 168853478879. The reversal of 168853478821 is 128874358861.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 157381997796 + 11471481025 = 396714^2 + 107105^2 .

It is a cyclic number.

It is not a de Polignac number, because 168853478821 - 2¹¹ = 168853476773 is a prime.

It is a super-2 number, since 2×168853478821² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 168853478821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (168853478621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84426739410 + 84426739411.

It is an arithmetic number, because the mean of its divisors is an integer number (84426739411).

Almost surely, 2^168853478821 is an apocalyptic number.

It is an amenable number.

168853478821 is a deficient number, since it is larger than the sum of its proper divisors (1).

168853478821 is an equidigital number, since it uses as much as digits as its factorization.

168853478821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20643840, while the sum is 61.

The spelling of 168853478821 in words is "one hundred sixty-eight billion, eight hundred fifty-three million, four hundred seventy-eight thousand, eight hundred twenty-one".