21075253 has 2 divisors, whose sum is σ = 21075254. Its totient is φ = 21075252.

The previous prime is 21075247. The next prime is 21075283. The reversal of 21075253 is 35257012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16589329 + 4485924 = 4073^2 + 2118^2 .

It is a cyclic number.

It is not a de Polignac number, because 21075253 - 2¹⁷ = 20944181 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21075283) 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, 10537626 + 10537627.

It is an arithmetic number, because the mean of its divisors is an integer number (10537627).

Almost surely, 2^21075253 is an apocalyptic number.

It is an amenable number.

21075253 is a deficient number, since it is larger than the sum of its proper divisors (1).

21075253 is an equidigital number, since it uses as much as digits as its factorization.

21075253 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2100, while the sum is 25.

The square root of 21075253 is about 4590.7791277734. The cubic root of 21075253 is about 276.2215760768.

The spelling of 21075253 in words is "twenty-one million, seventy-five thousand, two hundred fifty-three".