631500819661 has 4 divisors (see below), whose sum is σ = 631508002524. Its totient is φ = 631493636800.

The previous prime is 631500819659. The next prime is 631500819701. The reversal of 631500819661 is 166918005136.

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 502121046025 + 129379773636 = 708605^2 + 359694^2 .

It is a cyclic number.

It is not a de Polignac number, because 631500819661 - 2¹ = 631500819659 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 (631500819601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3457900 + ... + 3635941.

It is an arithmetic number, because the mean of its divisors is an integer number (157877000631).

Almost surely, 2^631500819661 is an apocalyptic number.

It is an amenable number.

631500819661 is a deficient number, since it is larger than the sum of its proper divisors (7182863).

631500819661 is an equidigital number, since it uses as much as digits as its factorization.

631500819661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7182862.

The product of its (nonzero) digits is 233280, while the sum is 46.

The spelling of 631500819661 in words is "six hundred thirty-one billion, five hundred million, eight hundred nineteen thousand, six hundred sixty-one".