155238009 has 4 divisors (see below), whose sum is σ = 206984016. Its totient is φ = 103492004.

The previous prime is 155238001. The next prime is 155238019. The reversal of 155238009 is 900832551.

155238009 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 155238009 - 2³ = 155238001 is a prime.

It is not an unprimeable number, because it can be changed into a prime (155238001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25872999 + ... + 25873004.

It is an arithmetic number, because the mean of its divisors is an integer number (51746004).

Almost surely, 2^155238009 is an apocalyptic number.

It is an amenable number.

155238009 is a deficient number, since it is larger than the sum of its proper divisors (51746007).

155238009 is an equidigital number, since it uses as much as digits as its factorization.

155238009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51746006.

The product of its (nonzero) digits is 10800, while the sum is 33.

The square root of 155238009 is about 12459.4546028307. The cubic root of 155238009 is about 537.4433431538.

It can be divided in two parts, 15523 and 8009, that added together give a palindrome (23532).

The spelling of 155238009 in words is "one hundred fifty-five million, two hundred thirty-eight thousand, nine".