63531063667561 has 4 divisors (see below), whose sum is σ = 72606929905792. Its totient is φ = 54455197429332.

The previous prime is 63531063667529. The next prime is 63531063667573. The reversal of 63531063667561 is 16576636013536.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 63531063667561 - 2⁵ = 63531063667529 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 63531063667496 and 63531063667505.

It is not an unprimeable number, because it can be changed into a prime (63531063667661) 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, 4537933119105 + ... + 4537933119118.

It is an arithmetic number, because the mean of its divisors is an integer number (18151732476448).

Almost surely, 2^{63531063667561} is an apocalyptic number.

It is an amenable number.

63531063667561 is a deficient number, since it is larger than the sum of its proper divisors (9075866238231).

63531063667561 is an equidigital number, since it uses as much as digits as its factorization.

63531063667561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9075866238230.

The product of its (nonzero) digits is 36741600, while the sum is 58.

The spelling of 63531063667561 in words is "sixty-three trillion, five hundred thirty-one billion, sixty-three million, six hundred sixty-seven thousand, five hundred sixty-one".