71661231 has 6 divisors (see below), whose sum is σ = 103510680. Its totient is φ = 47774148.

The previous prime is 71661209. The next prime is 71661241. The reversal of 71661231 is 13216617.

71661231 is a `hidden beast` number, since 7 + 16 + 612 + 31 = 666.

It is not a de Polignac number, because 71661231 - 2⁶ = 71661167 is a prime.

It is a super-2 number, since 2×71661231² = 10270664056870722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 71661195 and 71661204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71661241) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3981171 + ... + 3981188.

It is an arithmetic number, because the mean of its divisors is an integer number (17251780).

Almost surely, 2^71661231 is an apocalyptic number.

71661231 is a deficient number, since it is larger than the sum of its proper divisors (31849449).

71661231 is a wasteful number, since it uses less digits than its factorization.

71661231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7962365 (or 7962362 counting only the distinct ones).

The product of its digits is 1512, while the sum is 27.

The square root of 71661231 is about 8465.2956829635. The cubic root of 71661231 is about 415.3632683158.

Adding to 71661231 its reverse (13216617), we get a palindrome (84877848).

The spelling of 71661231 in words is "seventy-one million, six hundred sixty-one thousand, two hundred thirty-one".