21750133 has 2 divisors, whose sum is σ = 21750134. Its totient is φ = 21750132.

The previous prime is 21750119. The next prime is 21750149. The reversal of 21750133 is 33105712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11135569 + 10614564 = 3337^2 + 3258^2 .

It is a cyclic number.

It is not a de Polignac number, because 21750133 - 2⁵ = 21750101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21750163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10875066 + 10875067.

It is an arithmetic number, because the mean of its divisors is an integer number (10875067).

Almost surely, 2^21750133 is an apocalyptic number.

It is an amenable number.

21750133 is a deficient number, since it is larger than the sum of its proper divisors (1).

21750133 is an equidigital number, since it uses as much as digits as its factorization.

21750133 is an evil number, because the sum of its binary digits is even.

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

The square root of 21750133 is about 4663.7037856193. The cubic root of 21750133 is about 279.1390775537.

Adding to 21750133 its reverse (33105712), we get a palindrome (54855845).

The spelling of 21750133 in words is "twenty-one million, seven hundred fifty thousand, one hundred thirty-three".