71505131 has 4 divisors (see below), whose sum is σ = 71790264. Its totient is φ = 71220000.

The previous prime is 71505121. The next prime is 71505139. The reversal of 71505131 is 13150517.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13150517 = 199 ⋅66083.

It is a cyclic number.

It is not a de Polignac number, because 71505131 - 2⁶ = 71505067 is a prime.

It is a super-2 number, since 2×71505131² = 10225967518654322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 71505097 and 71505106.

It is not an unprimeable number, because it can be changed into a prime (71505139) 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, 142190 + ... + 142691.

It is an arithmetic number, because the mean of its divisors is an integer number (17947566).

Almost surely, 2^71505131 is an apocalyptic number.

71505131 is a deficient number, since it is larger than the sum of its proper divisors (285133).

71505131 is a wasteful number, since it uses less digits than its factorization.

71505131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 285132.

The product of its (nonzero) digits is 525, while the sum is 23.

The square root of 71505131 is about 8456.0706595913. The cubic root of 71505131 is about 415.0614531341.

Adding to 71505131 its reverse (13150517), we get a palindrome (84655648).

The spelling of 71505131 in words is "seventy-one million, five hundred five thousand, one hundred thirty-one".