21310433 has 2 divisors, whose sum is σ = 21310434. Its totient is φ = 21310432.

The previous prime is 21310417. The next prime is 21310439. The reversal of 21310433 is 33401312.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19651489 + 1658944 = 4433^2 + 1288^2 .

It is a cyclic number.

It is not a de Polignac number, because 21310433 - 2⁴ = 21310417 is a prime.

It is not a weakly prime, because it can be changed into another prime (21310439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10655216 + 10655217.

It is an arithmetic number, because the mean of its divisors is an integer number (10655217).

Almost surely, 2^21310433 is an apocalyptic number.

It is an amenable number.

21310433 is a deficient number, since it is larger than the sum of its proper divisors (1).

21310433 is an equidigital number, since it uses as much as digits as its factorization.

21310433 is an evil number, because the sum of its binary digits is even.

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

The square root of 21310433 is about 4616.3224540753. The cubic root of 21310433 is about 277.2452354328.

Adding to 21310433 its reverse (33401312), we get a palindrome (54711745).

The spelling of 21310433 in words is "twenty-one million, three hundred ten thousand, four hundred thirty-three".