1231326165 has 32 divisors (see below), whose sum is σ = 2027773440. Its totient is φ = 637760576.

The previous prime is 1231326149. The next prime is 1231326191. The reversal of 1231326165 is 5616231321.

It is a cyclic number.

It is not a de Polignac number, because 1231326165 - 2⁴ = 1231326149 is a prime.

It is a super-2 number, since 2×1231326165² = 3032328249227214450, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 65074 + ... + 81836.

It is an arithmetic number, because the mean of its divisors is an integer number (63367920).

Almost surely, 2^1231326165 is an apocalyptic number.

1231326165 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1231326165 is a deficient number, since it is larger than the sum of its proper divisors (796447275).

1231326165 is a wasteful number, since it uses less digits than its factorization.

1231326165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16913.

The product of its digits is 6480, while the sum is 30.

The square root of 1231326165 is about 35090.2574085742. The cubic root of 1231326165 is about 1071.8262012764.

Adding to 1231326165 its reverse (5616231321), we get a palindrome (6847557486).

The spelling of 1231326165 in words is "one billion, two hundred thirty-one million, three hundred twenty-six thousand, one hundred sixty-five".