21031753 has 2 divisors, whose sum is σ = 21031754. Its totient is φ = 21031752.

The previous prime is 21031741. The next prime is 21031781. The reversal of 21031753 is 35713012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10810944 + 10220809 = 3288^2 + 3197^2 .

It is a cyclic number.

It is not a de Polignac number, because 21031753 - 2⁵ = 21031721 is a prime.

It is not a weakly prime, because it can be changed into another prime (21031793) 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, 10515876 + 10515877.

It is an arithmetic number, because the mean of its divisors is an integer number (10515877).

Almost surely, 2^21031753 is an apocalyptic number.

It is an amenable number.

21031753 is a deficient number, since it is larger than the sum of its proper divisors (1).

21031753 is an equidigital number, since it uses as much as digits as its factorization.

21031753 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 630, while the sum is 22.

The square root of 21031753 is about 4586.0389226434. The cubic root of 21031753 is about 276.0314017692.

Adding to 21031753 its reverse (35713012), we get a palindrome (56744765).

The spelling of 21031753 in words is "twenty-one million, thirty-one thousand, seven hundred fifty-three".