21143742 has 8 divisors (see below), whose sum is σ = 42287496. Its totient is φ = 7047912.

The previous prime is 21143723. The next prime is 21143747. The reversal of 21143742 is 24734112.

It is a happy number.

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

21143742 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21143747) 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 in 3 ways as a sum of consecutive naturals, for example, 1761973 + ... + 1761984.

It is an arithmetic number, because the mean of its divisors is an integer number (5285937).

Almost surely, 2^21143742 is an apocalyptic number.

21143742 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21143742 is a wasteful number, since it uses less digits than its factorization.

21143742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3523962.

The product of its digits is 1344, while the sum is 24.

The square root of 21143742 is about 4598.2324865104. The cubic root of 21143742 is about 276.5204682333.

Adding to 21143742 its reverse (24734112), we get a palindrome (45877854).

The spelling of 21143742 in words is "twenty-one million, one hundred forty-three thousand, seven hundred forty-two".