20063581 has 2 divisors, whose sum is σ = 20063582. Its totient is φ = 20063580.

The previous prime is 20063579. The next prime is 20063591. The reversal of 20063581 is 18536002.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19660356 + 403225 = 4434^2 + 635^2 .

It is a cyclic number.

It is not a de Polignac number, because 20063581 - 2¹ = 20063579 is a prime.

It is a super-2 number, since 2×20063581² = 805094565087122, which contains 22 as substring.

Together with 20063579, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20063591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10031790 + 10031791.

It is an arithmetic number, because the mean of its divisors is an integer number (10031791).

Almost surely, 2^20063581 is an apocalyptic number.

It is an amenable number.

20063581 is a deficient number, since it is larger than the sum of its proper divisors (1).

20063581 is an equidigital number, since it uses as much as digits as its factorization.

20063581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 20063581 is about 4479.2388862395. The cubic root of 20063581 is about 271.7290996977.

Adding to 20063581 its reverse (18536002), we get a palindrome (38599583).

The spelling of 20063581 in words is "twenty million, sixty-three thousand, five hundred eighty-one".