201720641 has 2 divisors, whose sum is σ = 201720642. Its totient is φ = 201720640.

The previous prime is 201720637. The next prime is 201720647. The reversal of 201720641 is 146027102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 183196225 + 18524416 = 13535^2 + 4304^2 .

It is a cyclic number.

It is not a de Polignac number, because 201720641 - 2² = 201720637 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (201720647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100860320 + 100860321.

It is an arithmetic number, because the mean of its divisors is an integer number (100860321).

Almost surely, 2^201720641 is an apocalyptic number.

It is an amenable number.

201720641 is a deficient number, since it is larger than the sum of its proper divisors (1).

201720641 is an equidigital number, since it uses as much as digits as its factorization.

201720641 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 201720641 is about 14202.8391879934. The cubic root of 201720641 is about 586.4758227317.

Adding to 201720641 its reverse (146027102), we get a palindrome (347747743).

The spelling of 201720641 in words is "two hundred one million, seven hundred twenty thousand, six hundred forty-one".