21032424 has 96 divisors (see below), whose sum is σ = 67392000. Its totient is φ = 5798016.

The previous prime is 21032399. The next prime is 21032437. The reversal of 21032424 is 42423012.

21032424 is a `hidden beast` number, since 210 + 32 + 424 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21032397 and 21032406.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13897 + ... + 15335.

It is an arithmetic number, because the mean of its divisors is an integer number (702000).

Almost surely, 2^21032424 is an apocalyptic number.

21032424 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 21032424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33696000).

21032424 is an abundant number, since it is smaller than the sum of its proper divisors (46359576).

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

21032424 is a wasteful number, since it uses less digits than its factorization.

21032424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1487 (or 1480 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 21032424 is about 4586.1120788747. The cubic root of 21032424 is about 276.0343372528.

Adding to 21032424 its reverse (42423012), we get a palindrome (63455436).

The spelling of 21032424 in words is "twenty-one million, thirty-two thousand, four hundred twenty-four".