21231242 has 8 divisors (see below), whose sum is σ = 31998432. Its totient is φ = 10565100.

The previous prime is 21231241. The next prime is 21231253. The reversal of 21231242 is 24213212.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21231242.

It is not an unprimeable number, because it can be changed into a prime (21231241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24734 + ... + 25577.

It is an arithmetic number, because the mean of its divisors is an integer number (3999804).

Almost surely, 2^21231242 is an apocalyptic number.

21231242 is a deficient number, since it is larger than the sum of its proper divisors (10767190).

21231242 is a wasteful number, since it uses less digits than its factorization.

21231242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50524.

The product of its digits is 192, while the sum is 17.

The square root of 21231242 is about 4607.7371886860. The cubic root of 21231242 is about 276.9013885238.

Adding to 21231242 its reverse (24213212), we get a palindrome (45444454).

The spelling of 21231242 in words is "twenty-one million, two hundred thirty-one thousand, two hundred forty-two".