1213531165 has 32 divisors (see below), whose sum is σ = 1857816576. Its totient is φ = 738884160.

The previous prime is 1213531147. The next prime is 1213531169. The reversal of 1213531165 is 5611353121.

It is not a de Polignac number, because 1213531165 - 2¹¹ = 1213529117 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1213531169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 20097 + ... + 53206.

It is an arithmetic number, because the mean of its divisors is an integer number (58056768).

Almost surely, 2^1213531165 is an apocalyptic number.

It is an amenable number.

1213531165 is a deficient number, since it is larger than the sum of its proper divisors (644285411).

1213531165 is a wasteful number, since it uses less digits than its factorization.

1213531165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73369.

The product of its digits is 2700, while the sum is 28.

The square root of 1213531165 is about 34835.7742127256. The cubic root of 1213531165 is about 1066.6378188270.

Adding to 1213531165 its reverse (5611353121), we get a palindrome (6824884286).

It can be divided in two parts, 121353116 and 5, that added together give a palindrome (121353121).

The spelling of 1213531165 in words is "one billion, two hundred thirteen million, five hundred thirty-one thousand, one hundred sixty-five".