20241581 has 2 divisors, whose sum is σ = 20241582. Its totient is φ = 20241580.

The previous prime is 20241563. The next prime is 20241583. The reversal of 20241581 is 18514202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18139081 + 2102500 = 4259^2 + 1450^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20241581 is a prime.

It is a super-2 number, since 2×20241581² = 819443202759122, which contains 22 as substring.

Together with 20241583, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20241583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10120790 + 10120791.

It is an arithmetic number, because the mean of its divisors is an integer number (10120791).

Almost surely, 2^20241581 is an apocalyptic number.

It is an amenable number.

20241581 is a deficient number, since it is larger than the sum of its proper divisors (1).

20241581 is an equidigital number, since it uses as much as digits as its factorization.

20241581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 640, while the sum is 23.

The square root of 20241581 is about 4499.0644583069. The cubic root of 20241581 is about 272.5303100140.

Adding to 20241581 its reverse (18514202), we get a palindrome (38755783).

The spelling of 20241581 in words is "twenty million, two hundred forty-one thousand, five hundred eighty-one".