21022553 has 2 divisors, whose sum is σ = 21022554. Its totient is φ = 21022552.

The previous prime is 21022541. The next prime is 21022597. The reversal of 21022553 is 35522012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20912329 + 110224 = 4573^2 + 332^2 .

It is a cyclic number.

It is not a de Polignac number, because 21022553 - 2¹⁰ = 21021529 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21022753) 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, 10511276 + 10511277.

It is an arithmetic number, because the mean of its divisors is an integer number (10511277).

Almost surely, 2^21022553 is an apocalyptic number.

It is an amenable number.

21022553 is a deficient number, since it is larger than the sum of its proper divisors (1).

21022553 is an equidigital number, since it uses as much as digits as its factorization.

21022553 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 600, while the sum is 20.

The square root of 21022553 is about 4585.0357686718. The cubic root of 21022553 is about 275.9911474091.

Adding to 21022553 its reverse (35522012), we get a palindrome (56544565).

The spelling of 21022553 in words is "twenty-one million, twenty-two thousand, five hundred fifty-three".