721071 has 12 divisors (see below), whose sum is σ = 1121848. Its totient is φ = 443664.

The previous prime is 721057. The next prime is 721079. The reversal of 721071 is 170127.

721071 = 88² + 89² + ... + 141².

It is not a de Polignac number, because 721071 - 2⁷ = 720943 is a prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 721071.

It is not an unprimeable number, because it can be changed into a prime (721079) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2965 + ... + 3198.

2⁷²¹⁰⁷¹ is an apocalyptic number.

721071 is a deficient number, since it is larger than the sum of its proper divisors (400777).

721071 is a wasteful number, since it uses less digits than its factorization.

721071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6182 (or 6179 counting only the distinct ones).

The product of its (nonzero) digits is 98, while the sum is 18.

The square root of 721071 is about 849.1589957128. The cubic root of 721071 is about 89.6725135113.

Adding to 721071 its reverse (170127), we get a palindrome (891198).

The spelling of 721071 in words is "seven hundred twenty-one thousand, seventy-one", and thus it is an iban number.