631871639541 has 12 divisors (see below), whose sum is σ = 966391919532. Its totient is φ = 396468479616.

The previous prime is 631871639533. The next prime is 631871639551. The reversal of 631871639541 is 145936178136.

631871639541 is a `hidden beast` number, since 6 + 3 + 1 + 87 + 16 + 3 + 9 + 541 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 403569243441 + 228302396100 = 635271^2 + 477810^2 .

It is not a de Polignac number, because 631871639541 - 2³ = 631871639533 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (631871639551) 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 11 ways as a sum of consecutive naturals, for example, 2064939846 + ... + 2064940151.

It is an arithmetic number, because the mean of its divisors is an integer number (80532659961).

Almost surely, 2^631871639541 is an apocalyptic number.

It is an amenable number.

631871639541 is a deficient number, since it is larger than the sum of its proper divisors (334520279991).

631871639541 is a wasteful number, since it uses less digits than its factorization.

631871639541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4129880020 (or 4129880017 counting only the distinct ones).

The product of its digits is 3265920, while the sum is 54.

The spelling of 631871639541 in words is "six hundred thirty-one billion, eight hundred seventy-one million, six hundred thirty-nine thousand, five hundred forty-one".