501 has 4 divisors (see below), whose sum is σ = 672. Its totient is φ = 332.

The previous prime is 499. The next prime is 503. The reversal of 501 is 105.

Adding to 501 its reverse (105), we get a palindrome (606).

501 = 3^{2} + 4^{2} + ... + 11^{2}.

501 is nontrivially palindromic in base 9.

501 is an esthetic number in base 8, because in such base its adjacent digits differ by 1.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (499) and next prime (503).

It is a cyclic number.

It is a trimorphic number since its cube, 125751501, ends in 501.

It is not a de Polignac number, because 501 - 2^{1} = 499 is a prime.

It is a D-number.

It is an alternating number because its digits alternate between odd and even.

501 is an undulating number in base 9.

It is a plaindrome in base 12, base 14 and base 15.

It is a nialpdrome in base 8.

It is a self number, because there is not a number *n* which added to its sum of digits gives 501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 81 + ... + 86.

It is an arithmetic number, because the mean of its divisors is an integer number (168).

It is an amenable number.

501 is a deficient number, since it is larger than the sum of its proper divisors (171).

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

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

The sum of its prime factors is 170.

The product of its (nonzero) digits is 5, while the sum is 6.

The square root of 501 is about 22.3830292856. The cubic root of 501 is about 7.9422930730.

The spelling of 501 in words is "five hundred one", and thus it is an aban number.

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