51165 has 16 divisors (see below), whose sum is σ = 91200. Its totient is φ = 27216.

The previous prime is 51157. The next prime is 51169. The reversal of 51165 is 56115.

It is not a de Polignac number, because 51165 - 2³ = 51157 is a prime.

51165 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51169) 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 15 ways as a sum of consecutive naturals, for example, 55 + ... + 324.

It is an arithmetic number, because the mean of its divisors is an integer number (5700).

2⁵¹¹⁶⁵ is an apocalyptic number.

It is an amenable number.

51165 is a deficient number, since it is larger than the sum of its proper divisors (40035).

51165 is a wasteful number, since it uses less digits than its factorization.

51165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 393 (or 387 counting only the distinct ones).

The product of its digits is 150, while the sum is 18.

The square root of 51165 is about 226.1968169537. The cubic root of 51165 is about 37.1242475105.

Adding to 51165 its product of digits (150), we get a palindrome (51315).

Subtracting from 51165 its product of digits (150), we obtain a palindrome (51015).

Subtracting 51165 from its reverse (56115), we obtain a triangular number (4950 = T₉₉).

It can be divided in two parts, 511 and 65, that added together give a square (576 = 24²).

The spelling of 51165 in words is "fifty-one thousand, one hundred sixty-five".