71665231 has 4 divisors (see below), whose sum is σ = 78180264. Its totient is φ = 65150200.

The previous prime is 71665229. The next prime is 71665241. The reversal of 71665231 is 13256617.

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 71665231 - 2¹ = 71665229 is a prime.

It is a super-2 number, since 2×71665231² = 10271810668566722, 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 = 71665193 and 71665202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71665201) 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, 3257500 + ... + 3257521.

It is an arithmetic number, because the mean of its divisors is an integer number (19545066).

Almost surely, 2^71665231 is an apocalyptic number.

71665231 is a deficient number, since it is larger than the sum of its proper divisors (6515033).

71665231 is a wasteful number, since it uses less digits than its factorization.

71665231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6515032.

The product of its digits is 7560, while the sum is 31.

The square root of 71665231 is about 8465.5319383958. The cubic root of 71665231 is about 415.3709964468.

The spelling of 71665231 in words is "seventy-one million, six hundred sixty-five thousand, two hundred thirty-one".