21552328 has 32 divisors (see below), whose sum is σ = 48902400. Its totient is φ = 8692992.

The previous prime is 21552319. The next prime is 21552341. The reversal of 21552328 is 82325512.

It is a super-3 number, since 3×21552328³ (a number of 23 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 21552296 and 21552305.

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, 10368 + ... + 12271.

It is an arithmetic number, because the mean of its divisors is an integer number (1528200).

Almost surely, 2^21552328 is an apocalyptic number.

21552328 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21552328 is an abundant number, since it is smaller than the sum of its proper divisors (27350072).

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

21552328 is a wasteful number, since it uses less digits than its factorization.

21552328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22669 (or 22665 counting only the distinct ones).

The product of its digits is 4800, while the sum is 28.

The square root of 21552328 is about 4642.4484919060. The cubic root of 21552328 is about 278.2902959341.

The spelling of 21552328 in words is "twenty-one million, five hundred fifty-two thousand, three hundred twenty-eight".