21226742 has 8 divisors (see below), whose sum is σ = 31871232. Its totient is φ = 10603000.

The previous prime is 21226741. The next prime is 21226757. The reversal of 21226742 is 24762212.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21226741) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2309 + ... + 6912.

It is an arithmetic number, because the mean of its divisors is an integer number (3983904).

Almost surely, 2^21226742 is an apocalyptic number.

21226742 is a deficient number, since it is larger than the sum of its proper divisors (10644490).

21226742 is a wasteful number, since it uses less digits than its factorization.

21226742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10374.

The product of its digits is 2688, while the sum is 26.

The square root of 21226742 is about 4607.2488537087. The cubic root of 21226742 is about 276.8818238921.

Adding to 21226742 its reverse (24762212), we get a palindrome (45988954).

The spelling of 21226742 in words is "twenty-one million, two hundred twenty-six thousand, seven hundred forty-two".