21094440 has 64 divisors (see below), whose sum is σ = 65007360. Its totient is φ = 5472000.

The previous prime is 21094421. The next prime is 21094457. The reversal of 21094440 is 4449012.

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 21094440.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2065 + ... + 6815.

It is an arithmetic number, because the mean of its divisors is an integer number (1015740).

Almost surely, 2^21094440 is an apocalyptic number.

21094440 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 21094440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32503680).

21094440 is an abundant number, since it is smaller than the sum of its proper divisors (43912920).

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

21094440 is a wasteful number, since it uses less digits than its factorization.

21094440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4802 (or 4798 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 21094440 is about 4592.8683847896. The cubic root of 21094440 is about 276.3053750843.

The spelling of 21094440 in words is "twenty-one million, ninety-four thousand, four hundred forty".