201556643 has 2 divisors, whose sum is σ = 201556644. Its totient is φ = 201556642.

The previous prime is 201556559. The next prime is 201556661. The reversal of 201556643 is 346655102.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 201556643 - 2⁸ = 201556387 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (201556343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100778321 + 100778322.

It is an arithmetic number, because the mean of its divisors is an integer number (100778322).

Almost surely, 2^201556643 is an apocalyptic number.

201556643 is a deficient number, since it is larger than the sum of its proper divisors (1).

201556643 is an equidigital number, since it uses as much as digits as its factorization.

201556643 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21600, while the sum is 32.

The square root of 201556643 is about 14197.0645909639. The cubic root of 201556643 is about 586.3168455473.

The spelling of 201556643 in words is "two hundred one million, five hundred fifty-six thousand, six hundred forty-three".