21054144 has 56 divisors (see below), whose sum is σ = 56784240. Its totient is φ = 6882304.

The previous prime is 21054119. The next prime is 21054169. The reversal of 21054144 is 44145012.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21054119) and next prime (21054169).

It is a self number, because there is not a number n which added to its sum of digits gives 21054144.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9142 + ... + 11210.

Almost surely, 2^21054144 is an apocalyptic number.

21054144 is a gapful number since it is divisible by the number (24) 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 21054144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28392120).

21054144 is an abundant number, since it is smaller than the sum of its proper divisors (35730096).

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

21054144 is a wasteful number, since it uses less digits than its factorization.

21054144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2137 (or 2127 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 21.

The square root of 21054144 is about 4588.4794867145. The cubic root of 21054144 is about 276.1293239769.

Adding to 21054144 its reverse (44145012), we get a palindrome (65199156).

The spelling of 21054144 in words is "twenty-one million, fifty-four thousand, one hundred forty-four".