51555 has 16 divisors (see below), whose sum is σ = 94464. Its totient is φ = 23520.

The previous prime is 51551. The next prime is 51563. The reversal of 51555 is 55515.

51555 is nontrivially palindromic in base 4.

51555 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 51555 - 2² = 51551 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a nude number because it is divisible by every one of its digits.

It is a nialpdrome in base 9 and base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51551) 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, 141 + ... + 350.

It is an arithmetic number, because the mean of its divisors is an integer number (5904).

2⁵¹⁵⁵⁵ is an apocalyptic number.

51555 is a deficient number, since it is larger than the sum of its proper divisors (42909).

51555 is a wasteful number, since it uses less digits than its factorization.

51555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 506.

The product of its digits is 625, while the sum is 21.

The square root of 51555 is about 227.0572615003. The cubic root of 51555 is about 37.2183341236.

It can be divided in two parts, 51 and 555, that added together give a palindrome (606).

The spelling of 51555 in words is "fifty-one thousand, five hundred fifty-five".