201813643 has 2 divisors, whose sum is σ = 201813644. Its totient is φ = 201813642.

The previous prime is 201813631. The next prime is 201813691. The reversal of 201813643 is 346318102.

201813643 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-201813643 is a prime.

It is not a weakly prime, because it can be changed into another prime (201813343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100906821 + 100906822.

It is an arithmetic number, because the mean of its divisors is an integer number (100906822).

Almost surely, 2^201813643 is an apocalyptic number.

201813643 is a deficient number, since it is larger than the sum of its proper divisors (1).

201813643 is an equidigital number, since it uses as much as digits as its factorization.

201813643 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 201813643 is about 14206.1128743932. The cubic root of 201813643 is about 586.5659391819.

The spelling of 201813643 in words is "two hundred one million, eight hundred thirteen thousand, six hundred forty-three".