21110242 has 4 divisors (see below), whose sum is σ = 31665366. Its totient is φ = 10555120.

The previous prime is 21110233. The next prime is 21110249. The reversal of 21110242 is 24201112.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 19545241 + 1565001 = 4421^2 + 1251^2 .

It is not an unprimeable number, because it can be changed into a prime (21110249) 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 as a sum of consecutive naturals, namely, 5277559 + ... + 5277562.

Almost surely, 2^21110242 is an apocalyptic number.

21110242 is a deficient number, since it is larger than the sum of its proper divisors (10555124).

21110242 is a wasteful number, since it uses less digits than its factorization.

21110242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10555123.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 21110242 is about 4594.5883384695. The cubic root of 21110242 is about 276.3743519923.

Adding to 21110242 its reverse (24201112), we get a palindrome (45311354).

The spelling of 21110242 in words is "twenty-one million, one hundred ten thousand, two hundred forty-two".