51465 has 16 divisors (see below), whose sum is σ = 85248. Its totient is φ = 26496.

The previous prime is 51461. The next prime is 51473. The reversal of 51465 is 56415.

Added to its reverse (56415) it gives a triangular number (107880 = T₄₆₄).

It is a happy number.

It is not a de Polignac number, because 51465 - 2² = 51461 is a prime.

It is a Curzon number.

It is a nialpdrome in base 9.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 51465.

It is not an unprimeable number, because it can be changed into a prime (51461) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 669 + ... + 741.

It is an arithmetic number, because the mean of its divisors is an integer number (5328).

2⁵¹⁴⁶⁵ is an apocalyptic number.

It is an amenable number.

51465 is a deficient number, since it is larger than the sum of its proper divisors (33783).

51465 is a wasteful number, since it uses less digits than its factorization.

51465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128.

The product of its digits is 600, while the sum is 21.

The square root of 51465 is about 226.8589870382. The cubic root of 51465 is about 37.1966640551.

Adding to 51465 its reverse (56415), we get a triangular number (107880 = T₄₆₄).

Subtracting 51465 from its reverse (56415), we obtain a triangular number (4950 = T₉₉).

It can be divided in two parts, 5146 and 5, that added together give a triangular number (5151 = T₁₀₁).

The spelling of 51465 in words is "fifty-one thousand, four hundred sixty-five".