71721005 has 8 divisors (see below), whose sum is σ = 87277824. Its totient is φ = 56568400.

The previous prime is 71720959. The next prime is 71721071. The reversal of 71721005 is 50012717.

It is a happy number.

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

It is not a de Polignac number, because 71721005 - 2⁶ = 71720941 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 100661 + ... + 101370.

It is an arithmetic number, because the mean of its divisors is an integer number (10909728).

Almost surely, 2^71721005 is an apocalyptic number.

It is an amenable number.

71721005 is a deficient number, since it is larger than the sum of its proper divisors (15556819).

71721005 is a wasteful number, since it uses less digits than its factorization.

71721005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202107.

The product of its (nonzero) digits is 490, while the sum is 23.

The square root of 71721005 is about 8468.8254793684. The cubic root of 71721005 is about 415.4787236961.

The spelling of 71721005 in words is "seventy-one million, seven hundred twenty-one thousand, five".