71809739 has 8 divisors (see below), whose sum is σ = 72783360. Its totient is φ = 70840000.

The previous prime is 71809723. The next prime is 71809769. The reversal of 71809739 is 93790817.

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 71809739 - 2⁴ = 71809723 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 71809739.

It is not an unprimeable number, because it can be changed into a prime (71809709) 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, 61814 + ... + 62964.

It is an arithmetic number, because the mean of its divisors is an integer number (9097920).

Almost surely, 2^71809739 is an apocalyptic number.

71809739 is a deficient number, since it is larger than the sum of its proper divisors (973621).

71809739 is a wasteful number, since it uses less digits than its factorization.

71809739 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1941.

The product of its (nonzero) digits is 95256, while the sum is 44.

The square root of 71809739 is about 8474.0627210329. The cubic root of 71809739 is about 415.6499979990.

The spelling of 71809739 in words is "seventy-one million, eight hundred nine thousand, seven hundred thirty-nine".