21533293 has 2 divisors, whose sum is σ = 21533294. Its totient is φ = 21533292.

The previous prime is 21533279. The next prime is 21533333. The reversal of 21533293 is 39233512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18636489 + 2896804 = 4317^2 + 1702^2 .

It is a cyclic number.

It is not a de Polignac number, because 21533293 - 2⁹ = 21532781 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21533263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10766646 + 10766647.

It is an arithmetic number, because the mean of its divisors is an integer number (10766647).

Almost surely, 2^21533293 is an apocalyptic number.

It is an amenable number.

21533293 is a deficient number, since it is larger than the sum of its proper divisors (1).

21533293 is an equidigital number, since it uses as much as digits as its factorization.

21533293 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4860, while the sum is 28.

The square root of 21533293 is about 4640.3979355223. The cubic root of 21533293 is about 278.2083432086.

The spelling of 21533293 in words is "twenty-one million, five hundred thirty-three thousand, two hundred ninety-three".