155566009 has 2 divisors, whose sum is σ = 155566010. Its totient is φ = 155566008.

The previous prime is 155566001. The next prime is 155566069. The reversal of 155566009 is 900665551.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 137545984 + 18020025 = 11728^2 + 4245^2 .

It is an emirp because it is prime and its reverse (900665551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 155566009 - 2³ = 155566001 is a prime.

It is not a weakly prime, because it can be changed into another prime (155566001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77783004 + 77783005.

It is an arithmetic number, because the mean of its divisors is an integer number (77783005).

Almost surely, 2^155566009 is an apocalyptic number.

It is an amenable number.

155566009 is a deficient number, since it is larger than the sum of its proper divisors (1).

155566009 is an equidigital number, since it uses as much as digits as its factorization.

155566009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40500, while the sum is 37.

The square root of 155566009 is about 12472.6103522879. The cubic root of 155566009 is about 537.8215954669.

The spelling of 155566009 in words is "one hundred fifty-five million, five hundred sixty-six thousand, nine".