500988721 has 4 divisors (see below), whose sum is σ = 502984944. Its totient is φ = 498992500.

The previous prime is 500988703. The next prime is 500988731. The reversal of 500988721 is 127889005.

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, and also an emirpimes, since its reverse is a distinct semiprime: 127889005 = 5 ⋅25577801.

It is a cyclic number.

It is not a de Polignac number, because 500988721 - 2¹⁵ = 500955953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (500988731) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 997735 + ... + 998236.

It is an arithmetic number, because the mean of its divisors is an integer number (125746236).

Almost surely, 2^500988721 is an apocalyptic number.

It is an amenable number.

500988721 is a deficient number, since it is larger than the sum of its proper divisors (1996223).

500988721 is a wasteful number, since it uses less digits than its factorization.

500988721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1996222.

The product of its (nonzero) digits is 40320, while the sum is 40.

The square root of 500988721 is about 22382.7773299026. Note that the first 3 decimals coincide. The cubic root of 500988721 is about 794.2233471044.

The spelling of 500988721 in words is "five hundred million, nine hundred eighty-eight thousand, seven hundred twenty-one".