21186041 has 2 divisors, whose sum is σ = 21186042. Its totient is φ = 21186040.

The previous prime is 21186023. The next prime is 21186071. The reversal of 21186041 is 14068112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16168441 + 5017600 = 4021^2 + 2240^2 .

It is a cyclic number.

It is not a de Polignac number, because 21186041 - 2¹⁴ = 21169657 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21185998 and 21186016.

It is not a weakly prime, because it can be changed into another prime (21186071) 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, 10593020 + 10593021.

It is an arithmetic number, because the mean of its divisors is an integer number (10593021).

Almost surely, 2^21186041 is an apocalyptic number.

It is an amenable number.

21186041 is a deficient number, since it is larger than the sum of its proper divisors (1).

21186041 is an equidigital number, since it uses as much as digits as its factorization.

21186041 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 23.

The square root of 21186041 is about 4602.8296731467. The cubic root of 21186041 is about 276.7047425863.

The spelling of 21186041 in words is "twenty-one million, one hundred eighty-six thousand, forty-one".