• Deleting all the even digits from 25111 we obtain a prime of 779 digits.
5111 has 4
divisors (see below), whose sum is σ = 5400
Its totient is φ = 4824
The previous prime is 5107. The next prime is 5113. The reversal of 5111 is 1115.
It is a happy number.
It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1115 = 5 ⋅223.
It is a cyclic number.
It is not a de Polignac number, because 5111 - 22 = 5107 is a prime.
It is a super-2 number, since 2×51112 = 52244642, which contains 22 as substring.
It is a Duffinian number.
5111 is a modest number, since divided by 111 gives 5 as remainder.
It is a plaindrome in base 15.
It is a nialpdrome in base 10.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (5113) 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, 116 + ... + 153.
It is an arithmetic number, because the mean of its divisors is an integer number (1350).
25111 is an apocalyptic number.
5111 is a deficient number, since it is larger than the sum of its proper divisors (289).
5111 is a wasteful number, since it uses less digits than its factorization.
5111 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 288.
The product of its digits is 5, while the sum is 8.
The square root of 5111 is about 71.4912582069.
The cubic root of 5111 is about 17.2253726845.
Adding to 5111 its reverse (1115), we get a palindrome (6226).
It can be divided in two parts, 511 and 1, that added together give a 9-th power (512 = 29).
The spelling of 5111 in words is "five thousand, one hundred eleven".