503431455661 has 4 divisors (see below), whose sum is σ = 503441689212. Its totient is φ = 503421222112.

The previous prime is 503431455647. The next prime is 503431455691. The reversal of 503431455661 is 166554134305.

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 156286599561 + 347144856100 = 395331^2 + 589190^2 .

It is a cyclic number.

It is not a de Polignac number, because 503431455661 - 2⁷ = 503431455533 is a prime.

It is a super-4 number, since 4×503431455661⁴ (a number of 48 digits) contains 4444 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (503431455691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5042626 + ... + 5141491.

It is an arithmetic number, because the mean of its divisors is an integer number (125860422303).

Almost surely, 2^503431455661 is an apocalyptic number.

It is an amenable number.

503431455661 is a deficient number, since it is larger than the sum of its proper divisors (10233551).

503431455661 is a wasteful number, since it uses less digits than its factorization.

503431455661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10233550.

The product of its (nonzero) digits is 648000, while the sum is 43.

Adding to 503431455661 its reverse (166554134305), we get a palindrome (669985589966).

The spelling of 503431455661 in words is "five hundred three billion, four hundred thirty-one million, four hundred fifty-five thousand, six hundred sixty-one".