71681909 has 8 divisors (see below), whose sum is σ = 78839040. Its totient is φ = 64759536.

The previous prime is 71681887. The next prime is 71681921. The reversal of 71681909 is 90918617.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 71681909 - 2¹² = 71677813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71681609) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 58049 + ... + 59270.

It is an arithmetic number, because the mean of its divisors is an integer number (9854880).

Almost surely, 2^71681909 is an apocalyptic number.

It is an amenable number.

71681909 is a deficient number, since it is larger than the sum of its proper divisors (7157131).

71681909 is a wasteful number, since it uses less digits than its factorization.

71681909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117379.

The product of its (nonzero) digits is 27216, while the sum is 41.

The square root of 71681909 is about 8466.5169343715. The cubic root of 71681909 is about 415.4032157907.

The spelling of 71681909 in words is "seventy-one million, six hundred eighty-one thousand, nine hundred nine".