21827040 has 96 divisors (see below), whose sum is σ = 70670880. Its totient is φ = 5658624.

The previous prime is 21827027. The next prime is 21827041. The reversal of 21827040 is 4072812.

It is a tau number, because it is divible by the number of its divisors (96).

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

It is a self number, because there is not a number n which added to its sum of digits gives 21827040.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21827041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17146 + ... + 18374.

It is an arithmetic number, because the mean of its divisors is an integer number (736155).

Almost surely, 2^21827040 is an apocalyptic number.

21827040 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 21827040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35335440).

21827040 is an abundant number, since it is smaller than the sum of its proper divisors (48843840).

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

21827040 is a wasteful number, since it uses less digits than its factorization.

21827040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1284 (or 1276 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 24.

The square root of 21827040 is about 4671.9417804592. The cubic root of 21827040 is about 279.4676961694.

Adding to 21827040 its reverse (4072812), we get a palindrome (25899852).

The spelling of 21827040 in words is "twenty-one million, eight hundred twenty-seven thousand, forty".