21534841 has 2 divisors, whose sum is σ = 21534842. Its totient is φ = 21534840.

The previous prime is 21534839. The next prime is 21534889. The reversal of 21534841 is 14843512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17673616 + 3861225 = 4204^2 + 1965^2 .

It is a cyclic number.

It is not a de Polignac number, because 21534841 - 2¹ = 21534839 is a prime.

Together with 21534839, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21534041) 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, 10767420 + 10767421.

It is an arithmetic number, because the mean of its divisors is an integer number (10767421).

Almost surely, 2^21534841 is an apocalyptic number.

It is an amenable number.

21534841 is a deficient number, since it is larger than the sum of its proper divisors (1).

21534841 is an equidigital number, since it uses as much as digits as its factorization.

21534841 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3840, while the sum is 28.

The square root of 21534841 is about 4640.5647285648. The cubic root of 21534841 is about 278.2150097257.

The spelling of 21534841 in words is "twenty-one million, five hundred thirty-four thousand, eight hundred forty-one".