71518381 has 6 divisors (see below), whose sum is σ = 78611246. Its totient is φ = 65016600.

The previous prime is 71518351. The next prime is 71518397. The reversal of 71518381 is 18381517.

It can be written as a sum of positive squares in only one way, i.e., 68062500 + 3455881 = 8250^2 + 1859^2 .

It is not a de Polignac number, because 71518381 - 2¹³ = 71510189 is a prime.

It is a super-2 number, since 2×71518381² = 10229757641722322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71518351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 295410 + ... + 295651.

Almost surely, 2^71518381 is an apocalyptic number.

It is an amenable number.

71518381 is a deficient number, since it is larger than the sum of its proper divisors (7092865).

71518381 is a wasteful number, since it uses less digits than its factorization.

71518381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 591083 (or 591072 counting only the distinct ones).

The product of its digits is 6720, while the sum is 34.

The square root of 71518381 is about 8456.8540841143. The cubic root of 71518381 is about 415.0870887051.

Adding to 71518381 its reverse (18381517), we get a palindrome (89899898).

The spelling of 71518381 in words is "seventy-one million, five hundred eighteen thousand, three hundred eighty-one".