21342742 has 8 divisors (see below), whose sum is σ = 32465232. Its totient is φ = 10521000.

The previous prime is 21342721. The next prime is 21342773. The reversal of 21342742 is 24724312.

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

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 75009 + ... + 75292.

It is an arithmetic number, because the mean of its divisors is an integer number (4058154).

Almost surely, 2^21342742 is an apocalyptic number.

21342742 is a deficient number, since it is larger than the sum of its proper divisors (11122490).

21342742 is a wasteful number, since it uses less digits than its factorization.

21342742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150374.

The product of its digits is 2688, while the sum is 25.

The square root of 21342742 is about 4619.8205592858. The cubic root of 21342742 is about 277.3852762797.

The spelling of 21342742 in words is "twenty-one million, three hundred forty-two thousand, seven hundred forty-two".