21580432 has 40 divisors (see below), whose sum is σ = 43559712. Its totient is φ = 10348800.

The previous prime is 21580421. The next prime is 21580441. The reversal of 21580432 is 23408512.

It is a junction number, because it is equal to n+sod(n) for n = 21580397 and 21580406.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 43707 + ... + 44197.

Almost surely, 2^21580432 is an apocalyptic number.

It is an amenable number.

21580432 is an abundant number, since it is smaller than the sum of its proper divisors (21979280).

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

21580432 is a wasteful number, since it uses less digits than its factorization.

21580432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 607 (or 601 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 21580432 is about 4645.4743568338. The cubic root of 21580432 is about 278.4112058950.

Adding to 21580432 its reverse (23408512), we get a palindrome (44988944).

The spelling of 21580432 in words is "twenty-one million, five hundred eighty thousand, four hundred thirty-two".