501661321 has 8 divisors (see below), whose sum is σ = 573482304. Its totient is φ = 429879120.

The previous prime is 501661301. The next prime is 501661331. The reversal of 501661321 is 123166105.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-501661321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (501661301) 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, 27606 + ... + 42016.

It is an arithmetic number, because the mean of its divisors is an integer number (71685288).

Almost surely, 2^501661321 is an apocalyptic number.

It is an amenable number.

501661321 is a deficient number, since it is larger than the sum of its proper divisors (71820983).

501661321 is a wasteful number, since it uses less digits than its factorization.

501661321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19391.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 501661321 is about 22397.7972354426. The cubic root of 501661321 is about 794.5786150768.

The spelling of 501661321 in words is "five hundred one million, six hundred sixty-one thousand, three hundred twenty-one".