21441040 has 20 divisors (see below), whose sum is σ = 49850604. Its totient is φ = 8576384.

The previous prime is 21441031. The next prime is 21441089. The reversal of 21441040 is 4014412.

It can be written as a sum of positive squares in 2 ways, for example, as 10969344 + 10471696 = 3312^2 + 3236^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (16).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 133927 + ... + 134086.

Almost surely, 2^21441040 is an apocalyptic number.

21441040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21441040 is an abundant number, since it is smaller than the sum of its proper divisors (28409564).

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

21441040 is a wasteful number, since it uses less digits than its factorization.

21441040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 268026 (or 268020 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 21441040 is about 4630.4470626496. The cubic root of 21441040 is about 277.8104741364.

Adding to 21441040 its reverse (4014412), we get a palindrome (25455452).

The spelling of 21441040 in words is "twenty-one million, four hundred forty-one thousand, forty".