71989509 has 8 divisors (see below), whose sum is σ = 101632320. Its totient is φ = 45169856.

The previous prime is 71989487. The next prime is 71989553. The reversal of 71989509 is 90598917.

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 71989509 - 2¹² = 71985413 is a prime.

It is a super-2 number, since 2×71989509² = 10364978812122162, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71989909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 705729 + ... + 705830.

It is an arithmetic number, because the mean of its divisors is an integer number (12704040).

Almost surely, 2^71989509 is an apocalyptic number.

It is an amenable number.

71989509 is a deficient number, since it is larger than the sum of its proper divisors (29642811).

71989509 is a wasteful number, since it uses less digits than its factorization.

71989509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1411579.

The product of its (nonzero) digits is 204120, while the sum is 48.

The square root of 71989509 is about 8484.6631636147. The cubic root of 71989509 is about 415.9965579258.

The spelling of 71989509 in words is "seventy-one million, nine hundred eighty-nine thousand, five hundred nine".