2151231165 has 24 divisors (see below), whose sum is σ = 3857382360. Its totient is φ = 1107759744.

The previous prime is 2151231161. The next prime is 2151231169. The reversal of 2151231165 is 5611321512.

It is an interprime number because it is at equal distance from previous prime (2151231161) and next prime (2151231169).

It can be written as a sum of positive squares in 4 ways, for example, as 397045476 + 1754185689 = 19926^2 + 41883^2 .

It is not a de Polignac number, because 2151231165 - 2² = 2151231161 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2151231161) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 822922 + ... + 825531.

It is an arithmetic number, because the mean of its divisors is an integer number (160724265).

Almost surely, 2^2151231165 is an apocalyptic number.

It is an amenable number.

2151231165 is a deficient number, since it is larger than the sum of its proper divisors (1706151195).

2151231165 is a wasteful number, since it uses less digits than its factorization.

2151231165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1648493 (or 1648490 counting only the distinct ones).

The product of its digits is 1800, while the sum is 27.

The square root of 2151231165 is about 46381.3665710703. The cubic root of 2151231165 is about 1290.9091931938.

Adding to 2151231165 its reverse (5611321512), we get a palindrome (7762552677).

The spelling of 2151231165 in words is "two billion, one hundred fifty-one million, two hundred thirty-one thousand, one hundred sixty-five".