21430133 has 4 divisors (see below), whose sum is σ = 21445728. Its totient is φ = 21414540.

The previous prime is 21430121. The next prime is 21430139. The reversal of 21430133 is 33103412.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21430133 - 2⁴ = 21430117 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21430139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5513 + ... + 8558.

It is an arithmetic number, because the mean of its divisors is an integer number (5361432).

Almost surely, 2^21430133 is an apocalyptic number.

It is an amenable number.

21430133 is a deficient number, since it is larger than the sum of its proper divisors (15595).

21430133 is a wasteful number, since it uses less digits than its factorization.

21430133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15594.

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

The square root of 21430133 is about 4629.2691647818. The cubic root of 21430133 is about 277.7633589968.

Adding to 21430133 its reverse (33103412), we get a palindrome (54533545).

The spelling of 21430133 in words is "twenty-one million, four hundred thirty thousand, one hundred thirty-three".