21222542 has 8 divisors (see below), whose sum is σ = 34727832. Its totient is φ = 9646600.

The previous prime is 21222529. The next prime is 21222557. The reversal of 21222542 is 24522212.

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, 482309 + ... + 482352.

It is an arithmetic number, because the mean of its divisors is an integer number (4340979).

Almost surely, 2^21222542 is an apocalyptic number.

21222542 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21222542 is a deficient number, since it is larger than the sum of its proper divisors (13505290).

21222542 is a wasteful number, since it uses less digits than its factorization.

21222542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 964674.

The product of its digits is 640, while the sum is 20.

The square root of 21222542 is about 4606.7930276929. The cubic root of 21222542 is about 276.8635610742.

Adding to 21222542 its reverse (24522212), we get a palindrome (45744754).

It can be divided in two parts, 2122 and 2542, that added together give a palindrome (4664).

The spelling of 21222542 in words is "twenty-one million, two hundred twenty-two thousand, five hundred forty-two".