21349824 has 112 divisors (see below), whose sum is σ = 62032896. Its totient is φ = 6451200.

The previous prime is 21349813. The next prime is 21349837. The reversal of 21349824 is 42894312.

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, 101079 + ... + 101289.

Almost surely, 2^21349824 is an apocalyptic number.

21349824 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 21349824, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31016448).

21349824 is an abundant number, since it is smaller than the sum of its proper divisors (40683072).

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

21349824 is a wasteful number, since it uses less digits than its factorization.

21349824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 274 (or 264 counting only the distinct ones).

The product of its digits is 13824, while the sum is 33.

The square root of 21349824 is about 4620.5869756991. The cubic root of 21349824 is about 277.4159537700.

The spelling of 21349824 in words is "twenty-one million, three hundred forty-nine thousand, eight hundred twenty-four".