21421343 has 8 divisors (see below), whose sum is σ = 23464080. Its totient is φ = 19465600.

The previous prime is 21421333. The next prime is 21421373. The reversal of 21421343 is 34312412.

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 21421343 - 2²² = 17227039 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21421333) 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, 21233 + ... + 22218.

It is an arithmetic number, because the mean of its divisors is an integer number (2933010).

Almost surely, 2^21421343 is an apocalyptic number.

21421343 is a deficient number, since it is larger than the sum of its proper divisors (2042737).

21421343 is a wasteful number, since it uses less digits than its factorization.

21421343 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43497.

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

The square root of 21421343 is about 4628.3196734884. The cubic root of 21421343 is about 277.7253770608.

Adding to 21421343 its reverse (34312412), we get a palindrome (55733755).

The spelling of 21421343 in words is "twenty-one million, four hundred twenty-one thousand, three hundred forty-three".