155009 has 2 divisors, whose sum is σ = 155010. Its totient is φ = 155008.

The previous prime is 155003. The next prime is 155017. The reversal of 155009 is 900551.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 144400 + 10609 = 380^2 + 103^2 .

It is an emirp because it is prime and its reverse (900551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 155009 - 2⁸ = 154753 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (155003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77504 + 77505.

It is an arithmetic number, because the mean of its divisors is an integer number (77505).

2¹⁵⁵⁰⁰⁹ is an apocalyptic number.

It is an amenable number.

155009 is a deficient number, since it is larger than the sum of its proper divisors (1).

155009 is an equidigital number, since it uses as much as digits as its factorization.

155009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 225, while the sum is 20.

The square root of 155009 is about 393.7118235461. The cubic root of 155009 is about 53.7178932104.

The spelling of 155009 in words is "one hundred fifty-five thousand, nine".