21406342 has 8 divisors (see below), whose sum is σ = 32180256. Its totient is φ = 10679592.

The previous prime is 21406339. The next prime is 21406361. The reversal of 21406342 is 24360412.

It is a happy number.

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 polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10633 + ... + 12484.

It is an arithmetic number, because the mean of its divisors is an integer number (4022532).

Almost surely, 2^21406342 is an apocalyptic number.

21406342 is a deficient number, since it is larger than the sum of its proper divisors (10773914).

21406342 is a wasteful number, since it uses less digits than its factorization.

21406342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23582.

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 21406342 is about 4626.6988231351. The cubic root of 21406342 is about 277.6605331455.

Adding to 21406342 its reverse (24360412), we get a palindrome (45766754).

The spelling of 21406342 in words is "twenty-one million, four hundred six thousand, three hundred forty-two".