21120328 has 8 divisors (see below), whose sum is σ = 39600630. Its totient is φ = 10560160.

The previous prime is 21120317. The next prime is 21120349. The reversal of 21120328 is 82302112.

It can be written as a sum of positive squares in only one way, i.e., 15350724 + 5769604 = 3918^2 + 2402^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a hoax number, since the sum of its digits (19) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1320013 + ... + 1320028.

Almost surely, 2^21120328 is an apocalyptic number.

It is an amenable number.

21120328 is a deficient number, since it is larger than the sum of its proper divisors (18480302).

21120328 is a wasteful number, since it uses less digits than its factorization.

21120328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2640047 (or 2640043 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 21120328 is about 4595.6858030113. The cubic root of 21120328 is about 276.4183601393.

The spelling of 21120328 in words is "twenty-one million, one hundred twenty thousand, three hundred twenty-eight".