201540643 has 2 divisors, whose sum is σ = 201540644. Its totient is φ = 201540642.

The previous prime is 201540601. The next prime is 201540709. The reversal of 201540643 is 346045102.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-201540643 is a prime.

It is not a weakly prime, because it can be changed into another prime (201540043) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100770321 + 100770322.

It is an arithmetic number, because the mean of its divisors is an integer number (100770322).

Almost surely, 2^201540643 is an apocalyptic number.

201540643 is a deficient number, since it is larger than the sum of its proper divisors (1).

201540643 is an equidigital number, since it uses as much as digits as its factorization.

201540643 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 201540643 is about 14196.5010830134. The cubic root of 201540643 is about 586.3013307725.

Adding to 201540643 its reverse (346045102), we get a palindrome (547585745).

The spelling of 201540643 in words is "two hundred one million, five hundred forty thousand, six hundred forty-three".