531631631605 has 4 divisors (see below), whose sum is σ = 637957957932. Its totient is φ = 425305305280.

The previous prime is 531631631603. The next prime is 531631631611. The reversal of 531631631605 is 506136136135.

It is a happy number.

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 186491831409 + 345139800196 = 431847^2 + 587486^2 .

It is not a de Polignac number, because 531631631605 - 2¹ = 531631631603 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (531631631603) 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, 53163163156 + ... + 53163163165.

It is an arithmetic number, because the mean of its divisors is an integer number (159489489483).

Almost surely, 2^531631631605 is an apocalyptic number.

It is an amenable number.

531631631605 is a deficient number, since it is larger than the sum of its proper divisors (106326326327).

531631631605 is a wasteful number, since it uses less digits than its factorization.

531631631605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106326326326.

The product of its (nonzero) digits is 145800, while the sum is 40.

The spelling of 531631631605 in words is "five hundred thirty-one billion, six hundred thirty-one million, six hundred thirty-one thousand, six hundred five".