21559472 has 20 divisors (see below), whose sum is σ = 45569256. Its totient is φ = 9799680.

The previous prime is 21559463. The next prime is 21559513. The reversal of 21559472 is 27495512.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61073 + ... + 61424.

Almost surely, 2^21559472 is an apocalyptic number.

21559472 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21559472 is an abundant number, since it is smaller than the sum of its proper divisors (24009784).

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

21559472 is a wasteful number, since it uses less digits than its factorization.

21559472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122516 (or 122510 counting only the distinct ones).

The product of its digits is 25200, while the sum is 35.

The square root of 21559472 is about 4643.2178497245. The cubic root of 21559472 is about 278.3210410466.

The spelling of 21559472 in words is "twenty-one million, five hundred fifty-nine thousand, four hundred seventy-two".