21104237 has 8 divisors (see below), whose sum is σ = 26311872. Its totient is φ = 16444800.

The previous prime is 21104233. The next prime is 21104243. The reversal of 21104237 is 73240112.

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

It is a cyclic number.

It is not a de Polignac number, because 21104237 - 2² = 21104233 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21104233) 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, 136964 + ... + 137117.

It is an arithmetic number, because the mean of its divisors is an integer number (3288984).

Almost surely, 2^21104237 is an apocalyptic number.

It is an amenable number.

21104237 is a deficient number, since it is larger than the sum of its proper divisors (5207635).

21104237 is a wasteful number, since it uses less digits than its factorization.

21104237 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 274099.

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 21104237 is about 4593.9348058065. The cubic root of 21104237 is about 276.3481437759.

Adding to 21104237 its reverse (73240112), we get a palindrome (94344349).

The spelling of 21104237 in words is "twenty-one million, one hundred four thousand, two hundred thirty-seven".