168421889 has 2 divisors, whose sum is σ = 168421890. Its totient is φ = 168421888.

The previous prime is 168421837. The next prime is 168421921. The reversal of 168421889 is 988124861.

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., 158130625 + 10291264 = 12575^2 + 3208^2 .

It is a cyclic number.

It is not a de Polignac number, because 168421889 - 2²⁴ = 151644673 is a prime.

It is not a weakly prime, because it can be changed into another prime (168421819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84210944 + 84210945.

It is an arithmetic number, because the mean of its divisors is an integer number (84210945).

Almost surely, 2^168421889 is an apocalyptic number.

It is an amenable number.

168421889 is a deficient number, since it is larger than the sum of its proper divisors (1).

168421889 is an equidigital number, since it uses as much as digits as its factorization.

168421889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 221184, while the sum is 47.

The square root of 168421889 is about 12977.7459136785. The cubic root of 168421889 is about 552.2463379706.

The spelling of 168421889 in words is "one hundred sixty-eight million, four hundred twenty-one thousand, eight hundred eighty-nine".