71131431 has 16 divisors (see below), whose sum is σ = 108557568. Its totient is φ = 40584000.

The previous prime is 71131409. The next prime is 71131447. The reversal of 71131431 is 13413117.

It is not a de Polignac number, because 71131431 - 2⁹ = 71130919 is a prime.

It is a super-2 number, since 2×71131431² = 10119360952215522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 71131398 and 71131407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71131031) 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 15 ways as a sum of consecutive naturals, for example, 13756 + ... + 18206.

It is an arithmetic number, because the mean of its divisors is an integer number (6784848).

Almost surely, 2^71131431 is an apocalyptic number.

71131431 is a deficient number, since it is larger than the sum of its proper divisors (37426137).

71131431 is a wasteful number, since it uses less digits than its factorization.

71131431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5222.

The product of its digits is 252, while the sum is 21.

The square root of 71131431 is about 8433.9451622595. The cubic root of 71131431 is about 414.3371253395.

Adding to 71131431 its reverse (13413117), we get a palindrome (84544548).

The spelling of 71131431 in words is "seventy-one million, one hundred thirty-one thousand, four hundred thirty-one".