71318431 has 4 divisors (see below), whose sum is σ = 71337352. Its totient is φ = 71299512.

The previous prime is 71318399. The next prime is 71318437. The reversal of 71318431 is 13481317.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 71318431 - 2⁵ = 71318399 is a prime.

It is a super-2 number, since 2×71318431² = 10172637200603522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 71318431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71318437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1665 + ... + 12058.

It is an arithmetic number, because the mean of its divisors is an integer number (17834338).

Almost surely, 2^71318431 is an apocalyptic number.

71318431 is a deficient number, since it is larger than the sum of its proper divisors (18921).

71318431 is a wasteful number, since it uses less digits than its factorization.

71318431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18920.

The product of its digits is 2016, while the sum is 28.

The square root of 71318431 is about 8445.0240378580. The cubic root of 71318431 is about 414.6998962588.

Adding to 71318431 its reverse (13481317), we get a palindrome (84799748).

The spelling of 71318431 in words is "seventy-one million, three hundred eighteen thousand, four hundred thirty-one".