1155209 has 4 divisors (see below), whose sum is σ = 1260240. Its totient is φ = 1050180.

The previous prime is 1155179. The next prime is 1155211. The reversal of 1155209 is 9025511.

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 1155209 - 2¹² = 1151113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1155239) 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 in 3 ways as a sum of consecutive naturals, for example, 52499 + ... + 52520.

It is an arithmetic number, because the mean of its divisors is an integer number (315060).

2^1155209 is an apocalyptic number.

It is an amenable number.

1155209 is a deficient number, since it is larger than the sum of its proper divisors (105031).

1155209 is a wasteful number, since it uses less digits than its factorization.

1155209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105030.

The product of its (nonzero) digits is 450, while the sum is 23.

The square root of 1155209 is about 1074.8064942119. The cubic root of 1155209 is about 104.9269030172.

The spelling of 1155209 in words is "one million, one hundred fifty-five thousand, two hundred nine".