21104512 has 64 divisors (see below), whose sum is σ = 49437360. Its totient is φ = 8847360.

The previous prime is 21104507. The next prime is 21104527. The reversal of 21104512 is 21540112.

It is a tau number, because it is divible by the number of its divisors (64).

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

It is a congruent number.

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, 17728 + ... + 18880.

Almost surely, 2^21104512 is an apocalyptic number.

21104512 is a gapful number since it is divisible by the number (22) 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 21104512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24718680).

21104512 is an abundant number, since it is smaller than the sum of its proper divisors (28332848).

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

21104512 is a wasteful number, since it uses less digits than its factorization.

21104512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1191 (or 1179 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 21104512 is about 4593.9647364776. The cubic root of 21104512 is about 276.3493440943.

Adding to 21104512 its reverse (21540112), we get a palindrome (42644624).

Subtracting 21104512 from its reverse (21540112), we obtain a square (435600 = 660²).

The spelling of 21104512 in words is "twenty-one million, one hundred four thousand, five hundred twelve".