721107 has 12 divisors (see below), whose sum is σ = 1096680. Its totient is φ = 455328.

The previous prime is 721087. The next prime is 721109. The reversal of 721107 is 701127.

It is not a de Polignac number, because 721107 - 2⁶ = 721043 is a prime.

721107 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 721107.

It is not an unprimeable number, because it can be changed into a prime (721109) 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, 1938 + ... + 2279.

It is an arithmetic number, because the mean of its divisors is an integer number (91390).

2⁷²¹¹⁰⁷ is an apocalyptic number.

721107 is a deficient number, since it is larger than the sum of its proper divisors (375573).

721107 is a wasteful number, since it uses less digits than its factorization.

721107 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4242 (or 4239 counting only the distinct ones).

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

The square root of 721107 is about 849.1801928919. The cubic root of 721107 is about 89.6740058085.

It can be divided in two parts, 721 and 107, that added together give a palindrome (828).

The spelling of 721107 in words is "seven hundred twenty-one thousand, one hundred seven", and thus it is an iban number.