21433351 has 2 divisors, whose sum is σ = 21433352. Its totient is φ = 21433350.

The previous prime is 21433319. The next prime is 21433361. The reversal of 21433351 is 15333412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21433351 - 2⁵ = 21433319 is a prime.

It is a Chen prime.

It is equal to p_1355611 and since 21433351 and 1355611 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21433361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10716675 + 10716676.

It is an arithmetic number, because the mean of its divisors is an integer number (10716676).

Almost surely, 2^21433351 is an apocalyptic number.

21433351 is a deficient number, since it is larger than the sum of its proper divisors (1).

21433351 is an equidigital number, since it uses as much as digits as its factorization.

21433351 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1080, while the sum is 22.

The square root of 21433351 is about 4629.6167227968. The cubic root of 21433351 is about 277.7772615042. Note that the first 3 decimals are identical.

Adding to 21433351 its reverse (15333412), we get a palindrome (36766763).

The spelling of 21433351 in words is "twenty-one million, four hundred thirty-three thousand, three hundred fifty-one".