21074688 has 72 divisors (see below), whose sum is σ = 62342000. Its totient is φ = 7022592.

The previous prime is 21074681. The next prime is 21074689. The reversal of 21074688 is 88647012.

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (21074681) by changing a digit.

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, 5388 + ... + 8436.

Almost surely, 2^21074688 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21074688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31171000).

21074688 is an abundant number, since it is smaller than the sum of its proper divisors (41267312).

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

21074688 is an equidigital number, since it uses as much as digits as its factorization.

21074688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3074 (or 3054 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 21074688 is about 4590.7175909655. The cubic root of 21074688 is about 276.2191076748.

The spelling of 21074688 in words is "twenty-one million, seventy-four thousand, six hundred eighty-eight".