21129024 has 112 divisors (see below), whose sum is σ = 65024000. Its totient is φ = 5930496.

The previous prime is 21128971. The next prime is 21129037. The reversal of 21129024 is 42092112.

It is a tau number, because it is divible by the number of its divisors (112).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

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, 106077 + ... + 106275.

Almost surely, 2^21129024 is an apocalyptic number.

21129024 is a gapful number since it is divisible by the number (24) 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 21129024, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32512000).

21129024 is an abundant number, since it is smaller than the sum of its proper divisors (43894976).

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

21129024 is a wasteful number, since it uses less digits than its factorization.

21129024 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300 (or 290 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 21129024 is about 4596.6318103585. The cubic root of 21129024 is about 276.4562920665.

The spelling of 21129024 in words is "twenty-one million, one hundred twenty-nine thousand, twenty-four".