21244061 has 2 divisors, whose sum is σ = 21244062. Its totient is φ = 21244060.

The previous prime is 21244001. The next prime is 21244063. The reversal of 21244061 is 16044212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18438436 + 2805625 = 4294^2 + 1675^2 .

It is a cyclic number.

It is not a de Polignac number, because 21244061 - 2⁶ = 21243997 is a prime.

Together with 21244063, 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 (21244063) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10622030 + 10622031.

It is an arithmetic number, because the mean of its divisors is an integer number (10622031).

Almost surely, 2^21244061 is an apocalyptic number.

It is an amenable number.

21244061 is a deficient number, since it is larger than the sum of its proper divisors (1).

21244061 is an equidigital number, since it uses as much as digits as its factorization.

21244061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 21244061 is about 4609.1280086368. The cubic root of 21244061 is about 276.9571064880.

Adding to 21244061 its reverse (16044212), we get a palindrome (37288273).

The spelling of 21244061 in words is "twenty-one million, two hundred forty-four thousand, sixty-one".