1205306155 has 4 divisors (see below), whose sum is σ = 1446367392. Its totient is φ = 964244920.

The previous prime is 1205306131. The next prime is 1205306197. The reversal of 1205306155 is 5516035021.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1205306155 - 2⁷ = 1205306027 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 120530611 + ... + 120530620.

It is an arithmetic number, because the mean of its divisors is an integer number (361591848).

Almost surely, 2^1205306155 is an apocalyptic number.

1205306155 is a deficient number, since it is larger than the sum of its proper divisors (241061237).

1205306155 is an equidigital number, since it uses as much as digits as its factorization.

1205306155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241061236.

The product of its (nonzero) digits is 4500, while the sum is 28.

The square root of 1205306155 is about 34717.5194246363. The cubic root of 1205306155 is about 1064.2225526487. Note that the first 3 decimals are identical.

The spelling of 1205306155 in words is "one billion, two hundred five million, three hundred six thousand, one hundred fifty-five".