21424342 has 8 divisors (see below), whose sum is σ = 32186016. Its totient is φ = 10695672.

The previous prime is 21424327. The next prime is 21424357. The reversal of 21424342 is 24342412.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21424327) and next prime (21424357).

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6558 + ... + 9265.

It is an arithmetic number, because the mean of its divisors is an integer number (4023252).

Almost surely, 2^21424342 is an apocalyptic number.

21424342 is a deficient number, since it is larger than the sum of its proper divisors (10761674).

21424342 is a wasteful number, since it uses less digits than its factorization.

21424342 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16502.

The product of its digits is 1536, while the sum is 22.

The square root of 21424342 is about 4628.6436458211. The cubic root of 21424342 is about 277.7383370254.

Adding to 21424342 its reverse (24342412), we get a palindrome (45766754).

The spelling of 21424342 in words is "twenty-one million, four hundred twenty-four thousand, three hundred forty-two".