155396005209 has 27 divisors (see below), whose sum is σ = 226879673917. Its totient is φ = 102492780000.

The previous prime is 155396005199. The next prime is 155396005213. The reversal of 155396005209 is 902500693551.

The square root of 155396005209 is 394203.

It is a perfect power (a square), and thus also a powerful number.

155396005209 is a `hidden beast` number, since 1 + 5 + 5 + 39 + 600 + 5 + 2 + 0 + 9 = 666.

155396005209 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 3950499609 + 151445505600 = 62853^2 + 389160^2 .

It is not a de Polignac number, because 155396005209 - 2²⁵ = 155362450777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155396005309) 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 in 26 ways as a sum of consecutive naturals, for example, 119442859 + ... + 119444159.

Almost surely, 2^155396005209 is an apocalyptic number.

155396005209 is the 394203-rd square number.

155396005209 is the 197102-nd centered octagonal number.

It is an amenable number.

155396005209 is a deficient number, since it is larger than the sum of its proper divisors (71483668708).

155396005209 is an frugal number, since it uses more digits than its factorization.

155396005209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2810 (or 1405 counting only the distinct ones).

The product of its (nonzero) digits is 364500, while the sum is 45.

The spelling of 155396005209 in words is "one hundred fifty-five billion, three hundred ninety-six million, five thousand, two hundred nine".