21329424 has 60 divisors (see below), whose sum is σ = 63211356. Its totient is φ = 6690816.

The previous prime is 21329401. The next prime is 21329431. The reversal of 21329424 is 42492312.

21329424 is a `hidden beast` number, since 213 + 29 + 424 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 19079424 + 2250000 = 4368^2 + 1500^2 .

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1909 + ... + 6804.

Almost surely, 2^21329424 is an apocalyptic number.

21329424 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21329424 is an abundant number, since it is smaller than the sum of its proper divisors (41881932).

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

21329424 is a wasteful number, since it uses less digits than its factorization.

21329424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8744 (or 8735 counting only the distinct ones).

The product of its digits is 3456, while the sum is 27.

The square root of 21329424 is about 4618.3789363802. The cubic root of 21329424 is about 277.3275675782.

The spelling of 21329424 in words is "twenty-one million, three hundred twenty-nine thousand, four hundred twenty-four".