506165621 has 4 divisors (see below), whose sum is σ = 545101452. Its totient is φ = 467229792.

The previous prime is 506165609. The next prime is 506165651. The reversal of 506165621 is 126561605.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 102718225 + 403447396 = 10135^2 + 20086^2 .

It is a cyclic number.

It is not a de Polignac number, because 506165621 - 2⁶ = 506165557 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 (506165651) 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, 19467896 + ... + 19467921.

It is an arithmetic number, because the mean of its divisors is an integer number (136275363).

Almost surely, 2^506165621 is an apocalyptic number.

It is an amenable number.

506165621 is a deficient number, since it is larger than the sum of its proper divisors (38935831).

506165621 is a wasteful number, since it uses less digits than its factorization.

506165621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38935830.

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 506165621 is about 22498.1248329722. The cubic root of 506165621 is about 796.9496448872.

The spelling of 506165621 in words is "five hundred six million, one hundred sixty-five thousand, six hundred twenty-one".