71513231 has 2 divisors, whose sum is σ = 71513232. Its totient is φ = 71513230.

The previous prime is 71513227. The next prime is 71513243. The reversal of 71513231 is 13231517.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 71513231 - 2² = 71513227 is a prime.

It is a super-2 number, since 2×71513231² = 10228284416118722, which contains 22 as substring.

It is equal to p_4201835 and since 71513231 and 4201835 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 71513197 and 71513206.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71513261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35756615 + 35756616.

It is an arithmetic number, because the mean of its divisors is an integer number (35756616).

Almost surely, 2^71513231 is an apocalyptic number.

71513231 is a deficient number, since it is larger than the sum of its proper divisors (1).

71513231 is an equidigital number, since it uses as much as digits as its factorization.

71513231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 630, while the sum is 23.

The square root of 71513231 is about 8456.5495918844. The cubic root of 71513231 is about 415.0771250669.

Adding to 71513231 its reverse (13231517), we get a palindrome (84744748).

The spelling of 71513231 in words is "seventy-one million, five hundred thirteen thousand, two hundred thirty-one".