21788341 has 2 divisors, whose sum is σ = 21788342. Its totient is φ = 21788340.

The previous prime is 21788297. The next prime is 21788363. The reversal of 21788341 is 14388712.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11088900 + 10699441 = 3330^2 + 3271^2 .

It is a cyclic number.

It is not a de Polignac number, because 21788341 - 2¹⁹ = 21264053 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21788297 and 21788306.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21786341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10894170 + 10894171.

It is an arithmetic number, because the mean of its divisors is an integer number (10894171).

Almost surely, 2^21788341 is an apocalyptic number.

It is an amenable number.

21788341 is a deficient number, since it is larger than the sum of its proper divisors (1).

21788341 is an equidigital number, since it uses as much as digits as its factorization.

21788341 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10752, while the sum is 34.

The square root of 21788341 is about 4667.7983032689. The cubic root of 21788341 is about 279.3024345129.

The spelling of 21788341 in words is "twenty-one million, seven hundred eighty-eight thousand, three hundred forty-one".