508638549721 has 3 divisors (see below), whose sum is σ = 508639262911. Its totient is φ = 508637836532.

The previous prime is 508638549707. The next prime is 508638549763. The reversal of 508638549721 is 127945836805.

The square root of 508638549721 is 713189.

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, and also an emirpimes, since its reverse is a distinct semiprime: 127945836805 = 5 ⋅25589167361.

It can be written as a sum of positive squares in only one way, i.e., 496657058121 + 11981491600 = 704739^2 + 109460^2 .

It is not a de Polignac number, because 508638549721 - 2⁷ = 508638549593 is a prime.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (508638549701) 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, 356595 + ... + 1069783.

It is a 1-persistent number, because it is pandigital, but 2⋅508638549721 = 1017277099442 is not.

Almost surely, 2^508638549721 is an apocalyptic number.

508638549721 is the 713189-th square number.

508638549721 is the 356595-th centered octagonal number.

It is an amenable number.

508638549721 is a deficient number, since it is larger than the sum of its proper divisors (713190).

508638549721 is an frugal number, since it uses more digits than its factorization.

508638549721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1426378 (or 713189 counting only the distinct ones).

The product of its (nonzero) digits is 14515200, while the sum is 58.

The spelling of 508638549721 in words is "five hundred eight billion, six hundred thirty-eight million, five hundred forty-nine thousand, seven hundred twenty-one".