21421433 has 8 divisors (see below), whose sum is σ = 23409216. Its totient is φ = 19440400.

The previous prime is 21421427. The next prime is 21421451. The reversal of 21421433 is 33412412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21421433 - 2⁸ = 21421177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21421453) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6863 + ... + 9483.

It is an arithmetic number, because the mean of its divisors is an integer number (2926152).

Almost surely, 2^21421433 is an apocalyptic number.

It is an amenable number.

21421433 is a deficient number, since it is larger than the sum of its proper divisors (1987783).

21421433 is a wasteful number, since it uses less digits than its factorization.

21421433 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3375.

The product of its digits is 576, while the sum is 20.

The square root of 21421433 is about 4628.3293962293. The cubic root of 21421433 is about 277.7257660070.

Adding to 21421433 its reverse (33412412), we get a palindrome (54833845).

The spelling of 21421433 in words is "twenty-one million, four hundred twenty-one thousand, four hundred thirty-three".