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51281 = 192699
BaseRepresentation
bin1100100001010001
32121100022
430201101
53120111
61033225
7302336
oct144121
977308
1051281
113558a
1225815
131a459
141498d
15102db
hexc851

51281 has 4 divisors (see below), whose sum is σ = 54000. Its totient is φ = 48564.

The previous prime is 51263. The next prime is 51283. The reversal of 51281 is 18215.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18215 = 53643.

It is not a de Polignac number, because 51281 - 26 = 51217 is a prime.

It is a super-2 number, since 2×512812 = 5259481922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a plaindrome in base 11.

It is a nialpdrome in base 16.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 51281.

It is not an unprimeable number, because it can be changed into a prime (51283) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1331 + ... + 1368.

It is an arithmetic number, because the mean of its divisors is an integer number (13500).

251281 is an apocalyptic number.

It is an amenable number.

51281 is a deficient number, since it is larger than the sum of its proper divisors (2719).

51281 is a wasteful number, since it uses less digits than its factorization.

51281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2718.

The product of its digits is 80, while the sum is 17.

The square root of 51281 is about 226.4530856491. The cubic root of 51281 is about 37.1522820546.

Adding to 51281 its reverse (18215), we get a palindrome (69496).

The spelling of 51281 in words is "fifty-one thousand, two hundred eighty-one".

Divisors: 1 19 2699 51281