21580441 has 2 divisors, whose sum is σ = 21580442. Its totient is φ = 21580440.

The previous prime is 21580421. The next prime is 21580451. The reversal of 21580441 is 14408512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17816841 + 3763600 = 4221^2 + 1940^2 .

It is a cyclic number.

It is not a de Polignac number, because 21580441 - 2¹⁹ = 21056153 is a prime.

It is a super-3 number, since 3×21580441³ (a number of 23 digits) contains 333 as substring.

It is equal to p_1364344 and since 21580441 and 1364344 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (21580421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10790220 + 10790221.

It is an arithmetic number, because the mean of its divisors is an integer number (10790221).

Almost surely, 2^21580441 is an apocalyptic number.

It is an amenable number.

21580441 is a deficient number, since it is larger than the sum of its proper divisors (1).

21580441 is an equidigital number, since it uses as much as digits as its factorization.

21580441 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1280, while the sum is 25.

The square root of 21580441 is about 4645.4753255184. The cubic root of 21580441 is about 278.4112445983.

Adding to 21580441 its reverse (14408512), we get a palindrome (35988953).

It can be divided in two parts, 215 and 80441, that added together give a square (80656 = 284²).

The spelling of 21580441 in words is "twenty-one million, five hundred eighty thousand, four hundred forty-one".