635543641 has 2 divisors, whose sum is σ = 635543642. Its totient is φ = 635543640.

The previous prime is 635543639. The next prime is 635543651. The reversal of 635543641 is 146345536.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 603734041 + 31809600 = 24571^2 + 5640^2 .

It is a cyclic number.

It is not a de Polignac number, because 635543641 - 2¹ = 635543639 is a prime.

Together with 635543639, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 635543641.

It is not a weakly prime, because it can be changed into another prime (635543651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 317771820 + 317771821.

It is an arithmetic number, because the mean of its divisors is an integer number (317771821).

Almost surely, 2^635543641 is an apocalyptic number.

It is an amenable number.

635543641 is a deficient number, since it is larger than the sum of its proper divisors (1).

635543641 is an equidigital number, since it uses as much as digits as its factorization.

635543641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 129600, while the sum is 37.

The square root of 635543641 is about 25209.9908964680. The cubic root of 635543641 is about 859.7690208066.

The spelling of 635543641 in words is "six hundred thirty-five million, five hundred forty-three thousand, six hundred forty-one".