501505661 has 8 divisors (see below), whose sum is σ = 536163264. Its totient is φ = 467421120.

The previous prime is 501505643. The next prime is 501505679. The reversal of 501505661 is 166505105.

It is an interprime number because it is at equal distance from previous prime (501505643) and next prime (501505679).

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

It is not a de Polignac number, because 501505661 - 2¹⁸ = 501243517 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (501505691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 141455 + ... + 144956.

It is an arithmetic number, because the mean of its divisors is an integer number (67020408).

Almost surely, 2^501505661 is an apocalyptic number.

It is an amenable number.

501505661 is a deficient number, since it is larger than the sum of its proper divisors (34657603).

501505661 is a wasteful number, since it uses less digits than its factorization.

501505661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 286531.

The product of its (nonzero) digits is 4500, while the sum is 29.

The square root of 501505661 is about 22394.3220705607. The cubic root of 501505661 is about 794.4964235684.

The spelling of 501505661 in words is "five hundred one million, five hundred five thousand, six hundred sixty-one".