168551989 has 2 divisors, whose sum is σ = 168551990. Its totient is φ = 168551988.

The previous prime is 168551969. The next prime is 168552017. The reversal of 168551989 is 989155861.

168551989 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., 125216100 + 43335889 = 11190^2 + 6583^2 .

It is a cyclic number.

It is not a de Polignac number, because 168551989 - 2¹⁹ = 168027701 is a prime.

It is a super-2 number, since 2×168551989² = 56819545991712242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (168551939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84275994 + 84275995.

It is an arithmetic number, because the mean of its divisors is an integer number (84275995).

Almost surely, 2^168551989 is an apocalyptic number.

It is an amenable number.

168551989 is a deficient number, since it is larger than the sum of its proper divisors (1).

168551989 is an equidigital number, since it uses as much as digits as its factorization.

168551989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 777600, while the sum is 52.

The square root of 168551989 is about 12982.7573727618. The cubic root of 168551989 is about 552.3884983456.

The spelling of 168551989 in words is "one hundred sixty-eight million, five hundred fifty-one thousand, nine hundred eighty-nine".