155238409 has 2 divisors, whose sum is σ = 155238410. Its totient is φ = 155238408.

The previous prime is 155238361. The next prime is 155238427. The reversal of 155238409 is 904832551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 154455184 + 783225 = 12428^2 + 885^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-155238409 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (155238439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77619204 + 77619205.

It is an arithmetic number, because the mean of its divisors is an integer number (77619205).

Almost surely, 2^155238409 is an apocalyptic number.

It is an amenable number.

155238409 is a deficient number, since it is larger than the sum of its proper divisors (1).

155238409 is an equidigital number, since it uses as much as digits as its factorization.

155238409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 43200, while the sum is 37.

The square root of 155238409 is about 12459.4706548874. The cubic root of 155238409 is about 537.4438047614.

It can be divided in two parts, 15523 and 8409, that added together give a palindrome (23932).

The spelling of 155238409 in words is "one hundred fifty-five million, two hundred thirty-eight thousand, four hundred nine".