631643563 has 2 divisors, whose sum is σ = 631643564. Its totient is φ = 631643562.

The previous prime is 631643531. The next prime is 631643567. The reversal of 631643563 is 365346136.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 631643563 - 2⁵ = 631643531 is a prime.

It is not a weakly prime, because it can be changed into another prime (631643567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315821781 + 315821782.

It is an arithmetic number, because the mean of its divisors is an integer number (315821782).

Almost surely, 2^631643563 is an apocalyptic number.

631643563 is a deficient number, since it is larger than the sum of its proper divisors (1).

631643563 is an equidigital number, since it uses as much as digits as its factorization.

631643563 is an evil number, because the sum of its binary digits is even.

The product of its digits is 116640, while the sum is 37.

The square root of 631643563 is about 25132.5200288391. The cubic root of 631643563 is about 858.0067244453.

Adding to 631643563 its reverse (365346136), we get a palindrome (996989699).

The spelling of 631643563 in words is "six hundred thirty-one million, six hundred forty-three thousand, five hundred sixty-three".