21031033 has 2 divisors, whose sum is σ = 21031034. Its totient is φ = 21031032.

The previous prime is 21031027. The next prime is 21031063. The reversal of 21031033 is 33013012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19079424 + 1951609 = 4368^2 + 1397^2 .

It is a cyclic number.

It is not a de Polignac number, because 21031033 - 2¹⁷ = 20899961 is a prime.

It is not a weakly prime, because it can be changed into another prime (21031063) 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, 10515516 + 10515517.

It is an arithmetic number, because the mean of its divisors is an integer number (10515517).

Almost surely, 2^21031033 is an apocalyptic number.

It is an amenable number.

21031033 is a deficient number, since it is larger than the sum of its proper divisors (1).

21031033 is an equidigital number, since it uses as much as digits as its factorization.

21031033 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 54, while the sum is 13.

The square root of 21031033 is about 4585.9604228558. The cubic root of 21031033 is about 276.0282518514.

Adding to 21031033 its reverse (33013012), we get a palindrome (54044045).

It can be divided in two parts, 2103 and 1033, that added together give a square (3136 = 56²).

The spelling of 21031033 in words is "twenty-one million, thirty-one thousand, thirty-three".