71511 has 12 divisors (see below), whose sum is σ = 105336. Its totient is φ = 43120.

The previous prime is 71503. The next prime is 71527. The reversal of 71511 is 11517.

Added to its reverse (11517) it gives a triangular number (83028 = T₄₀₇).

It is not a de Polignac number, because 71511 - 2³ = 71503 is a prime.

It is a super-2 number, since 2×71511² = 10227646242, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71551) 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, 265 + ... + 461.

It is an arithmetic number, because the mean of its divisors is an integer number (8778).

2⁷¹⁵¹¹ is an apocalyptic number.

71511 is a deficient number, since it is larger than the sum of its proper divisors (33825).

71511 is a wasteful number, since it uses less digits than its factorization.

71511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222 (or 211 counting only the distinct ones).

The product of its digits is 35, while the sum is 15.

The square root of 71511 is about 267.4154071852. The cubic root of 71511 is about 41.5072808632.

Adding to 71511 its reverse (11517), we get a triangular number (83028 = T₄₀₇).

The spelling of 71511 in words is "seventy-one thousand, five hundred eleven".