21380896 has 12 divisors (see below), whose sum is σ = 42093702. Its totient is φ = 10690432.

The previous prime is 21380893. The next prime is 21380921. The reversal of 21380896 is 69808312.

It can be written as a sum of positive squares in only one way, i.e., 20976400 + 404496 = 4580^2 + 636^2 .

It is not an unprimeable number, because it can be changed into a prime (21380893) 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 as a sum of consecutive naturals, namely, 334045 + ... + 334108.

Almost surely, 2^21380896 is an apocalyptic number.

It is an amenable number.

21380896 is a deficient number, since it is larger than the sum of its proper divisors (20712806).

21380896 is an equidigital number, since it uses as much as digits as its factorization.

21380896 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 668163 (or 668155 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 21380896 is about 4623.9480965945. The cubic root of 21380896 is about 277.5504699481.

The spelling of 21380896 in words is "twenty-one million, three hundred eighty thousand, eight hundred ninety-six".