155115409 has 2 divisors, whose sum is σ = 155115410. Its totient is φ = 155115408.

The previous prime is 155115379. The next prime is 155115419. The reversal of 155115409 is 904511551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 134212225 + 20903184 = 11585^2 + 4572^2 .

It is a cyclic number.

It is not a de Polignac number, because 155115409 - 2⁵ = 155115377 is a prime.

It is not a weakly prime, because it can be changed into another prime (155115419) 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, 77557704 + 77557705.

It is an arithmetic number, because the mean of its divisors is an integer number (77557705).

Almost surely, 2^155115409 is an apocalyptic number.

It is an amenable number.

155115409 is a deficient number, since it is larger than the sum of its proper divisors (1).

155115409 is an equidigital number, since it uses as much as digits as its factorization.

155115409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4500, while the sum is 31.

The square root of 155115409 is about 12454.5336725226. The cubic root of 155115409 is about 537.3018230288.

The spelling of 155115409 in words is "one hundred fifty-five million, one hundred fifteen thousand, four hundred nine".