155120509 has 2 divisors, whose sum is σ = 155120510. Its totient is φ = 155120508.

The previous prime is 155120501. The next prime is 155120519. The reversal of 155120509 is 905021551.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 109935225 + 45185284 = 10485^2 + 6722^2 .

It is a cyclic number.

It is not a de Polignac number, because 155120509 - 2³ = 155120501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155120501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77560254 + 77560255.

It is an arithmetic number, because the mean of its divisors is an integer number (77560255).

Almost surely, 2^155120509 is an apocalyptic number.

It is an amenable number.

155120509 is a deficient number, since it is larger than the sum of its proper divisors (1).

155120509 is an equidigital number, since it uses as much as digits as its factorization.

155120509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2250, while the sum is 28.

The square root of 155120509 is about 12454.7384155590. The cubic root of 155120509 is about 537.3077115675.

The spelling of 155120509 in words is "one hundred fifty-five million, one hundred twenty thousand, five hundred nine".