21104042 has 4 divisors (see below), whose sum is σ = 31656066. Its totient is φ = 10552020.

The previous prime is 21104033. The next prime is 21104059. The reversal of 21104042 is 24040112.

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., 20241001 + 863041 = 4499^2 + 929^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5276009 + ... + 5276012.

Almost surely, 2^21104042 is an apocalyptic number.

21104042 is a deficient number, since it is larger than the sum of its proper divisors (10552024).

21104042 is a wasteful number, since it uses less digits than its factorization.

21104042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10552023.

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 21104042 is about 4593.9135821215. The cubic root of 21104042 is about 276.3472926347.

Adding to 21104042 its reverse (24040112), we get a palindrome (45144154).

The spelling of 21104042 in words is "twenty-one million, one hundred four thousand, forty-two".