71231731 has 4 divisors (see below), whose sum is σ = 71604864. Its totient is φ = 70858600.

The previous prime is 71231729. The next prime is 71231737. The reversal of 71231731 is 13713217.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13713217 = 7 ⋅1959031.

It is a cyclic number.

It is not a de Polignac number, because 71231731 - 2¹ = 71231729 is a prime.

It is a super-2 number, since 2×71231731² = 10147919002512722, 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 = 71231696 and 71231705.

It is not an unprimeable number, because it can be changed into a prime (71231737) 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, 186280 + ... + 186661.

It is an arithmetic number, because the mean of its divisors is an integer number (17901216).

Almost surely, 2^71231731 is an apocalyptic number.

71231731 is a deficient number, since it is larger than the sum of its proper divisors (373133).

71231731 is a wasteful number, since it uses less digits than its factorization.

71231731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 373132.

The product of its digits is 882, while the sum is 25.

The square root of 71231731 is about 8439.8892765249. The cubic root of 71231731 is about 414.5317814158.

Adding to 71231731 its reverse (13713217), we get a palindrome (84944948).

The spelling of 71231731 in words is "seventy-one million, two hundred thirty-one thousand, seven hundred thirty-one".