168722881 has 2 divisors, whose sum is σ = 168722882. Its totient is φ = 168722880.

The previous prime is 168722819. The next prime is 168722993. The reversal of 168722881 is 188227861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 149230656 + 19492225 = 12216^2 + 4415^2 .

It is an emirp because it is prime and its reverse (188227861) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 168722881 - 2⁷ = 168722753 is a prime.

It is a super-2 number, since 2×168722881² = 56934821145880322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (168722581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84361440 + 84361441.

It is an arithmetic number, because the mean of its divisors is an integer number (84361441).

Almost surely, 2^168722881 is an apocalyptic number.

It is an amenable number.

168722881 is a deficient number, since it is larger than the sum of its proper divisors (1).

168722881 is an equidigital number, since it uses as much as digits as its factorization.

168722881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 86016, while the sum is 43.

The square root of 168722881 is about 12989.3372040301. The cubic root of 168722881 is about 552.5751210620.

The spelling of 168722881 in words is "one hundred sixty-eight million, seven hundred twenty-two thousand, eight hundred eighty-one".