21031433 has 2 divisors, whose sum is σ = 21031434. Its totient is φ = 21031432.

The previous prime is 21031421. The next prime is 21031457. The reversal of 21031433 is 33413012.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19254544 + 1776889 = 4388^2 + 1333^2 .

It is a cyclic number.

It is not a de Polignac number, because 21031433 - 2¹² = 21027337 is a prime.

It is not a weakly prime, because it can be changed into another prime (21031463) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10515716 + 10515717.

It is an arithmetic number, because the mean of its divisors is an integer number (10515717).

Almost surely, 2^21031433 is an apocalyptic number.

It is an amenable number.

21031433 is a deficient number, since it is larger than the sum of its proper divisors (1).

21031433 is an equidigital number, since it uses as much as digits as its factorization.

21031433 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 17.

The square root of 21031433 is about 4586.0040340148. The cubic root of 21031433 is about 276.0300018146.

Adding to 21031433 its reverse (33413012), we get a palindrome (54444445).

The spelling of 21031433 in words is "twenty-one million, thirty-one thousand, four hundred thirty-three".