641630263 has 2 divisors, whose sum is σ = 641630264. Its totient is φ = 641630262.

The previous prime is 641630261. The next prime is 641630267. The reversal of 641630263 is 362036146.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 641630263 - 2¹ = 641630261 is a prime.

Together with 641630261, it forms a pair of twin primes.

It is equal to p_33381076 and since 641630263 and 33381076 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (641630261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320815131 + 320815132.

It is an arithmetic number, because the mean of its divisors is an integer number (320815132).

Almost surely, 2^641630263 is an apocalyptic number.

641630263 is a deficient number, since it is larger than the sum of its proper divisors (1).

641630263 is an equidigital number, since it uses as much as digits as its factorization.

641630263 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15552, while the sum is 31.

The square root of 641630263 is about 25330.4216901338. The cubic root of 641630263 is about 862.5049837421.

The spelling of 641630263 in words is "six hundred forty-one million, six hundred thirty thousand, two hundred sixty-three".