21776328 has 48 divisors (see below), whose sum is σ = 67404480. Its totient is φ = 6221664.

The previous prime is 21776327. The next prime is 21776333. The reversal of 21776328 is 82367712.

21776328 is a `hidden beast` number, since 2 + 17 + 7 + 632 + 8 = 666.

It is a super-2 number, since 2×21776328² = 948416922327168, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 21776292 and 21776301.

It is not an unprimeable number, because it can be changed into a prime (21776327) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 21100 + ... + 22107.

It is an arithmetic number, because the mean of its divisors is an integer number (1404260).

Almost surely, 2^21776328 is an apocalyptic number.

21776328 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21776328 is an abundant number, since it is smaller than the sum of its proper divisors (45628152).

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

21776328 is a wasteful number, since it uses less digits than its factorization.

21776328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43226 (or 43219 counting only the distinct ones).

The product of its digits is 28224, while the sum is 36.

The square root of 21776328 is about 4666.5113307481. The cubic root of 21776328 is about 279.2510939516.

The spelling of 21776328 in words is "twenty-one million, seven hundred seventy-six thousand, three hundred twenty-eight".