21045837 has 8 divisors (see below), whose sum is σ = 28416640. Its totient is φ = 13852800.

The previous prime is 21045811. The next prime is 21045853. The reversal of 21045837 is 73854012.

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

It is not a de Polignac number, because 21045837 - 2¹⁰ = 21044813 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 (21045137) 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, 44164 + ... + 44637.

It is an arithmetic number, because the mean of its divisors is an integer number (3552080).

Almost surely, 2^21045837 is an apocalyptic number.

It is an amenable number.

21045837 is a deficient number, since it is larger than the sum of its proper divisors (7370803).

21045837 is an equidigital number, since it uses as much as digits as its factorization.

21045837 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88883.

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 21045837 is about 4587.5741955853. The cubic root of 21045837 is about 276.0930032089.

Adding to 21045837 its reverse (73854012), we get a palindrome (94899849).

The spelling of 21045837 in words is "twenty-one million, forty-five thousand, eight hundred thirty-seven".