155609 has 2 divisors, whose sum is σ = 155610. Its totient is φ = 155608.

The previous prime is 155599. The next prime is 155621. The reversal of 155609 is 906551.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 126025 + 29584 = 355^2 + 172^2 .

It is a cyclic number.

It is not a de Polignac number, because 155609 - 2⁴ = 155593 is a prime.

It is a Chen prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 155609.

It is not a weakly prime, because it can be changed into another prime (155689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77804 + 77805.

It is an arithmetic number, because the mean of its divisors is an integer number (77805).

2¹⁵⁵⁶⁰⁹ is an apocalyptic number.

It is an amenable number.

155609 is a deficient number, since it is larger than the sum of its proper divisors (1).

155609 is an equidigital number, since it uses as much as digits as its factorization.

155609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1350, while the sum is 26.

The square root of 155609 is about 394.4730662542. The cubic root of 155609 is about 53.7871133621.

It can be divided in two parts, 155 and 609, that multiplied together give a triangular number (94395 = T₄₃₄).

The spelling of 155609 in words is "one hundred fifty-five thousand, six hundred nine".