201968581 has 2 divisors, whose sum is σ = 201968582. Its totient is φ = 201968580.

The previous prime is 201968563. The next prime is 201968593. The reversal of 201968581 is 185869102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 201895681 + 72900 = 14209^2 + 270^2 .

It is a cyclic number.

It is not a de Polignac number, because 201968581 - 2¹³ = 201960389 is a prime.

It is a super-2 number, since 2×201968581² = 81582615422307122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201968521) 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, 100984290 + 100984291.

It is an arithmetic number, because the mean of its divisors is an integer number (100984291).

Almost surely, 2^201968581 is an apocalyptic number.

It is an amenable number.

201968581 is a deficient number, since it is larger than the sum of its proper divisors (1).

201968581 is an equidigital number, since it uses as much as digits as its factorization.

201968581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 34560, while the sum is 40.

The square root of 201968581 is about 14211.5650440055. The cubic root of 201968581 is about 586.7160084978.

The spelling of 201968581 in words is "two hundred one million, nine hundred sixty-eight thousand, five hundred eighty-one".