501021 has 12 divisors (see below), whose sum is σ = 730080. Its totient is φ = 331080.

The previous prime is 501019. The next prime is 501029. The reversal of 501021 is 120105.

It is a happy number.

It is not a de Polignac number, because 501021 - 2¹ = 501019 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 500994 and 501012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (501029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1456 + ... + 1766.

It is an arithmetic number, because the mean of its divisors is an integer number (60840).

2⁵⁰¹⁰²¹ is an apocalyptic number.

It is an amenable number.

501021 is a deficient number, since it is larger than the sum of its proper divisors (229059).

501021 is a wasteful number, since it uses less digits than its factorization.

501021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 496 (or 493 counting only the distinct ones).

The product of its (nonzero) digits is 10, while the sum is 9.

The square root of 501021 is about 707.8283690274. The cubic root of 501021 is about 79.4240404165.

Adding to 501021 its reverse (120105), we get a palindrome (621126).

The spelling of 501021 in words is "five hundred one thousand, twenty-one".