21430433 has 2 divisors, whose sum is σ = 21430434. Its totient is φ = 21430432.

The previous prime is 21430403. The next prime is 21430439. The reversal of 21430433 is 33403412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21049744 + 380689 = 4588^2 + 617^2 .

It is a cyclic number.

It is not a de Polignac number, because 21430433 - 2⁶ = 21430369 is a prime.

It is not a weakly prime, because it can be changed into another prime (21430439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10715216 + 10715217.

It is an arithmetic number, because the mean of its divisors is an integer number (10715217).

Almost surely, 2^21430433 is an apocalyptic number.

It is an amenable number.

21430433 is a deficient number, since it is larger than the sum of its proper divisors (1).

21430433 is an equidigital number, since it uses as much as digits as its factorization.

21430433 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 20.

The square root of 21430433 is about 4629.3015671913. The cubic root of 21430433 is about 277.7646551253.

Adding to 21430433 its reverse (33403412), we get a palindrome (54833845).

The spelling of 21430433 in words is "twenty-one million, four hundred thirty thousand, four hundred thirty-three".