21837120 has 168 divisors, whose sum is σ = 74163936. Its totient is φ = 5440512.

The previous prime is 21837119. The next prime is 21837149. The reversal of 21837120 is 2173812.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 507819 + ... + 507861.

It is an arithmetic number, because the mean of its divisors is an integer number (441452).

Almost surely, 2^21837120 is an apocalyptic number.

21837120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21837120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37081968).

21837120 is an abundant number, since it is smaller than the sum of its proper divisors (52326816).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21837120 is a wasteful number, since it uses less digits than its factorization.

21837120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109 (or 76 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 21837120 is about 4673.0204365057. The cubic root of 21837120 is about 279.5107101075.

The spelling of 21837120 in words is "twenty-one million, eight hundred thirty-seven thousand, one hundred twenty".