179969989 has 2 divisors, whose sum is σ = 179969990. Its totient is φ = 179969988.

The previous prime is 179969987. The next prime is 179970023. The reversal of 179969989 is 989969971.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 163405089 + 16564900 = 12783^2 + 4070^2 .

It is an emirp because it is prime and its reverse (989969971) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 179969989 - 2¹ = 179969987 is a prime.

Together with 179969987, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (179969983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 89984994 + 89984995.

It is an arithmetic number, because the mean of its divisors is an integer number (89984995).

Almost surely, 2^179969989 is an apocalyptic number.

It is an amenable number.

179969989 is a deficient number, since it is larger than the sum of its proper divisors (1).

179969989 is an equidigital number, since it uses as much as digits as its factorization.

179969989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19840464, while the sum is 67.

The square root of 179969989 is about 13415.2893744414. The cubic root of 179969989 is about 564.5902362153.

The spelling of 179969989 in words is "one hundred seventy-nine million, nine hundred sixty-nine thousand, nine hundred eighty-nine".