51516 has 36 divisors (see below), whose sum is σ = 137592. Its totient is φ = 16848.

The previous prime is 51511. The next prime is 51517. The reversal of 51516 is 61515.

51516 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an Ulam number.

It is a nialpdrome in base 9.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51511) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 946 + ... + 998.

It is an arithmetic number, because the mean of its divisors is an integer number (3822).

2⁵¹⁵¹⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51516, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68796).

51516 is an abundant number, since it is smaller than the sum of its proper divisors (86076).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51516 is a wasteful number, since it uses less digits than its factorization.

51516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72 (or 58 counting only the distinct ones).

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

The square root of 51516 is about 226.9713638325. The cubic root of 51516 is about 37.2089468595.

Subtracting 51516 from its reverse (61515), we obtain a palindrome (9999).

It can be divided in two parts, 5 and 1516, that added together give a square (1521 = 39²).

The spelling of 51516 in words is "fifty-one thousand, five hundred sixteen".