721671 has 8 divisors (see below), whose sum is σ = 1004160. Its totient is φ = 460152.

The previous prime is 721663. The next prime is 721687. The reversal of 721671 is 176127.

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

It is not a de Polignac number, because 721671 - 2³ = 721663 is a prime.

It is a plaindrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721621) 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, 5161 + ... + 5298.

It is an arithmetic number, because the mean of its divisors is an integer number (125520).

2⁷²¹⁶⁷¹ is an apocalyptic number.

721671 is a deficient number, since it is larger than the sum of its proper divisors (282489).

721671 is a wasteful number, since it uses less digits than its factorization.

721671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10485.

The product of its digits is 588, while the sum is 24.

The square root of 721671 is about 849.5122129787. The cubic root of 721671 is about 89.6973786502.

Adding to 721671 its reverse (176127), we get a palindrome (897798).

The spelling of 721671 in words is "seven hundred twenty-one thousand, six hundred seventy-one".