21837489 has 8 divisors (see below), whose sum is σ = 29185632. Its totient is φ = 14523840.

The previous prime is 21837467. The next prime is 21837509. The reversal of 21837489 is 98473812.

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

It is not a de Polignac number, because 21837489 - 2²⁰ = 20788913 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21837489.

It is not an unprimeable number, because it can be changed into a prime (21837089) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7107 + ... + 9704.

It is an arithmetic number, because the mean of its divisors is an integer number (3648204).

Almost surely, 2^21837489 is an apocalyptic number.

It is an amenable number.

21837489 is a deficient number, since it is larger than the sum of its proper divisors (7348143).

21837489 is a wasteful number, since it uses less digits than its factorization.

21837489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17247.

The product of its digits is 96768, while the sum is 42.

The square root of 21837489 is about 4673.0599182976. The cubic root of 21837489 is about 279.5122844737.

The spelling of 21837489 in words is "twenty-one million, eight hundred thirty-seven thousand, four hundred eighty-nine".