21133733 has 2 divisors, whose sum is σ = 21133734. Its totient is φ = 21133732.

The previous prime is 21133727. The next prime is 21133747. The reversal of 21133733 is 33733112.

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., 18515809 + 2617924 = 4303^2 + 1618^2 .

It is a cyclic number.

It is not a de Polignac number, because 21133733 - 2⁸ = 21133477 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21133699 and 21133708.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21133753) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10566866 + 10566867.

It is an arithmetic number, because the mean of its divisors is an integer number (10566867).

Almost surely, 2^21133733 is an apocalyptic number.

It is an amenable number.

21133733 is a deficient number, since it is larger than the sum of its proper divisors (1).

21133733 is an equidigital number, since it uses as much as digits as its factorization.

21133733 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1134, while the sum is 23.

The square root of 21133733 is about 4597.1440047055. The cubic root of 21133733 is about 276.4768283673.

Adding to 21133733 its reverse (33733112), we get a palindrome (54866845).

The spelling of 21133733 in words is "twenty-one million, one hundred thirty-three thousand, seven hundred thirty-three".