21104460 has 144 divisors (see below), whose sum is σ = 71547840. Its totient is φ = 4999680.

The previous prime is 21104453. The next prime is 21104491. The reversal of 21104460 is 6440112.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 67705 + ... + 68015.

It is an arithmetic number, because the mean of its divisors is an integer number (496860).

Almost surely, 2^21104460 is an apocalyptic number.

21104460 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 21104460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35773920).

21104460 is an abundant number, since it is smaller than the sum of its proper divisors (50443380).

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

21104460 is a wasteful number, since it uses less digits than its factorization.

21104460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 368 (or 363 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 21104460 is about 4593.9590768748. The cubic root of 21104460 is about 276.3491171258.

Adding to 21104460 its reverse (6440112), we get a palindrome (27544572).

The spelling of 21104460 in words is "twenty-one million, one hundred four thousand, four hundred sixty".