21828413 has 2 divisors, whose sum is σ = 21828414. Its totient is φ = 21828412.

The previous prime is 21828383. The next prime is 21828437. The reversal of 21828413 is 31482812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21780889 + 47524 = 4667^2 + 218^2 .

It is a cyclic number.

It is not a de Polignac number, because 21828413 - 2⁶ = 21828349 is a prime.

It is a super-2 number, since 2×21828413² = 952959228197138, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is equal to p_1379063 and since 21828413 and 1379063 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21828463) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10914206 + 10914207.

It is an arithmetic number, because the mean of its divisors is an integer number (10914207).

Almost surely, 2^21828413 is an apocalyptic number.

It is an amenable number.

21828413 is a deficient number, since it is larger than the sum of its proper divisors (1).

21828413 is an equidigital number, since it uses as much as digits as its factorization.

21828413 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3072, while the sum is 29.

The square root of 21828413 is about 4672.0887191919. The cubic root of 21828413 is about 279.4735558905.

The spelling of 21828413 in words is "twenty-one million, eight hundred twenty-eight thousand, four hundred thirteen".