21548428 has 24 divisors (see below), whose sum is σ = 41524560. Its totient is φ = 9702720.

The previous prime is 21548399. The next prime is 21548491. The reversal of 21548428 is 82484512.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 21548393 and 21548402.

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 7 ways as a sum of consecutive naturals, for example, 2550 + ... + 7042.

It is an arithmetic number, because the mean of its divisors is an integer number (1730190).

Almost surely, 2^21548428 is an apocalyptic number.

It is an amenable number.

21548428 is a deficient number, since it is larger than the sum of its proper divisors (19976132).

21548428 is a wasteful number, since it uses less digits than its factorization.

21548428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4617 (or 4615 counting only the distinct ones).

The product of its digits is 20480, while the sum is 34.

The square root of 21548428 is about 4642.0284359319. The cubic root of 21548428 is about 278.2735089212.

It can be divided in two parts, 215484 and 28, that added together give a palindrome (215512).

The spelling of 21548428 in words is "twenty-one million, five hundred forty-eight thousand, four hundred twenty-eight".