21092549 has 2 divisors, whose sum is σ = 21092550. Its totient is φ = 21092548.

The previous prime is 21092543. The next prime is 21092557. The reversal of 21092549 is 94529012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19201924 + 1890625 = 4382^2 + 1375^2 .

It is a cyclic number.

It is not a de Polignac number, because 21092549 - 2⁸ = 21092293 is a prime.

It is a Chen prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21092543) 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, 10546274 + 10546275.

It is an arithmetic number, because the mean of its divisors is an integer number (10546275).

Almost surely, 2^21092549 is an apocalyptic number.

It is an amenable number.

21092549 is a deficient number, since it is larger than the sum of its proper divisors (1).

21092549 is an equidigital number, since it uses as much as digits as its factorization.

21092549 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6480, while the sum is 32.

The square root of 21092549 is about 4592.6625175382. The cubic root of 21092549 is about 276.2971184208.

The spelling of 21092549 in words is "twenty-one million, ninety-two thousand, five hundred forty-nine".