21342406 has 4 divisors (see below), whose sum is σ = 32013612. Its totient is φ = 10671202.

The previous prime is 21342383. The next prime is 21342407. The reversal of 21342406 is 60424312.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21342407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5335600 + ... + 5335603.

It is an arithmetic number, because the mean of its divisors is an integer number (8003403).

Almost surely, 2^21342406 is an apocalyptic number.

21342406 is a deficient number, since it is larger than the sum of its proper divisors (10671206).

21342406 is a wasteful number, since it uses less digits than its factorization.

21342406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10671205.

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

The square root of 21342406 is about 4619.7841940939. The cubic root of 21342406 is about 277.3838206413.

Adding to 21342406 its reverse (60424312), we get a palindrome (81766718).

The spelling of 21342406 in words is "twenty-one million, three hundred forty-two thousand, four hundred six".