631387535563 has 4 divisors (see below), whose sum is σ = 658839167568. Its totient is φ = 603935903560.

The previous prime is 631387535543. The next prime is 631387535683. The reversal of 631387535563 is 365535783136.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-631387535563 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (631387535543) 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, 13725815968 + ... + 13725816013.

It is an arithmetic number, because the mean of its divisors is an integer number (164709791892).

Almost surely, 2^631387535563 is an apocalyptic number.

631387535563 is a deficient number, since it is larger than the sum of its proper divisors (27451632005).

631387535563 is a wasteful number, since it uses less digits than its factorization.

631387535563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27451632004.

The product of its digits is 20412000, while the sum is 55.

The spelling of 631387535563 in words is "six hundred thirty-one billion, three hundred eighty-seven million, five hundred thirty-five thousand, five hundred sixty-three".