21311033 has 2 divisors, whose sum is σ = 21311034. Its totient is φ = 21311032.

The previous prime is 21310999. The next prime is 21311051. The reversal of 21311033 is 33011312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13454224 + 7856809 = 3668^2 + 2803^2 .

It is a cyclic number.

It is not a de Polignac number, because 21311033 - 2¹⁸ = 21048889 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21310999 and 21311017.

It is not a weakly prime, because it can be changed into another prime (21311053) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10655516 + 10655517.

It is an arithmetic number, because the mean of its divisors is an integer number (10655517).

Almost surely, 2^21311033 is an apocalyptic number.

It is an amenable number.

21311033 is a deficient number, since it is larger than the sum of its proper divisors (1).

21311033 is an equidigital number, since it uses as much as digits as its factorization.

21311033 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54, while the sum is 14.

The square root of 21311033 is about 4616.3874404127. The cubic root of 21311033 is about 277.2478373755.

Adding to 21311033 its reverse (33011312), we get a palindrome (54322345).

The spelling of 21311033 in words is "twenty-one million, three hundred eleven thousand, thirty-three".