495209171521 has 3 divisors (see below), whose sum is σ = 495209875233. Its totient is φ = 495208467810.

The previous prime is 495209171519. The next prime is 495209171543. The reversal of 495209171521 is 125171902594.

The square root of 495209171521 is 703711.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 495209171521 - 2¹ = 495209171519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (495209171621) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 351856 + ... + 1055566.

It is an arithmetic number, because the mean of its divisors is an integer number (165069958411).

Almost surely, 2^495209171521 is an apocalyptic number.

495209171521 is the 703711-st square number.

495209171521 is the 351856-th centered octagonal number.

It is an amenable number.

495209171521 is a deficient number, since it is larger than the sum of its proper divisors (703712).

495209171521 is an frugal number, since it uses more digits than its factorization.

495209171521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1407422 (or 703711 counting only the distinct ones).

The product of its (nonzero) digits is 226800, while the sum is 46.

The spelling of 495209171521 in words is "four hundred ninety-five billion, two hundred nine million, one hundred seventy-one thousand, five hundred twenty-one".