501721 has 8 divisors (see below), whose sum is σ = 579744. Its totient is φ = 429120.

The previous prime is 501719. The next prime is 501731. The reversal of 501721 is 127105.

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 501721 - 2¹ = 501719 is a prime.

501721 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 501695 and 501704.

It is not an unprimeable number, because it can be changed into a prime (501701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1155 + ... + 1528.

It is an arithmetic number, because the mean of its divisors is an integer number (72468).

2⁵⁰¹⁷²¹ is an apocalyptic number.

It is an amenable number.

501721 is a deficient number, since it is larger than the sum of its proper divisors (78023).

501721 is a wasteful number, since it uses less digits than its factorization.

501721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2711.

The product of its (nonzero) digits is 70, while the sum is 16.

The square root of 501721 is about 708.3226665864. The cubic root of 501721 is about 79.4610122241.

Adding to 501721 its reverse (127105), we get a palindrome (628826).

It can be divided in two parts, 50 and 1721, that added together give a palindrome (1771).

The spelling of 501721 in words is "five hundred one thousand, seven hundred twenty-one".