21042104 has 32 divisors (see below), whose sum is σ = 40439520. Its totient is φ = 10262016.

The previous prime is 21042103. The next prime is 21042127. The reversal of 21042104 is 40124012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21042103) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 79877 + ... + 80139.

It is an arithmetic number, because the mean of its divisors is an integer number (1263735).

Almost surely, 2^21042104 is an apocalyptic number.

It is an amenable number.

21042104 is a deficient number, since it is larger than the sum of its proper divisors (19397416).

21042104 is a wasteful number, since it uses less digits than its factorization.

21042104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 479 (or 475 counting only the distinct ones).

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

The square root of 21042104 is about 4587.1673176373. The cubic root of 21042104 is about 276.0766782682.

Adding to 21042104 its reverse (40124012), we get a palindrome (61166116).

The spelling of 21042104 in words is "twenty-one million, forty-two thousand, one hundred four".