21580201 has 2 divisors, whose sum is σ = 21580202. Its totient is φ = 21580200.

The previous prime is 21580199. The next prime is 21580217. The reversal of 21580201 is 10208512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17438976 + 4141225 = 4176^2 + 2035^2 .

It is a cyclic number.

It is not a de Polignac number, because 21580201 - 2¹ = 21580199 is a prime.

Together with 21580199, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21580271) 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, 10790100 + 10790101.

It is an arithmetic number, because the mean of its divisors is an integer number (10790101).

Almost surely, 2^21580201 is an apocalyptic number.

It is an amenable number.

21580201 is a deficient number, since it is larger than the sum of its proper divisors (1).

21580201 is an equidigital number, since it uses as much as digits as its factorization.

21580201 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 160, while the sum is 19.

The square root of 21580201 is about 4645.4494938596. The cubic root of 21580201 is about 278.4102125071.

Adding to 21580201 its reverse (10208512), we get a palindrome (31788713).

The spelling of 21580201 in words is "twenty-one million, five hundred eighty thousand, two hundred one".