506165721 has 16 divisors (see below), whose sum is σ = 685926720. Its totient is φ = 331948800.

The previous prime is 506165717. The next prime is 506165729. The reversal of 506165721 is 127561605.

It is not a de Polignac number, because 506165721 - 2² = 506165717 is a prime.

It is not an unprimeable number, because it can be changed into a prime (506165729) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 86746 + ... + 92396.

It is an arithmetic number, because the mean of its divisors is an integer number (42870420).

Almost surely, 2^506165721 is an apocalyptic number.

It is an amenable number.

506165721 is a deficient number, since it is larger than the sum of its proper divisors (179760999).

506165721 is a wasteful number, since it uses less digits than its factorization.

506165721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6136.

The product of its (nonzero) digits is 12600, while the sum is 33.

The square root of 506165721 is about 22498.1270553795. The cubic root of 506165721 is about 796.9496973700.

The spelling of 506165721 in words is "five hundred six million, one hundred sixty-five thousand, seven hundred twenty-one".