21380163 has 16 divisors (see below), whose sum is σ = 33703680. Its totient is φ = 11795616.

The previous prime is 21380153. The next prime is 21380171. The reversal of 21380163 is 36108312.

It is not a de Polignac number, because 21380163 - 2⁵ = 21380131 is a prime.

It is a super-2 number, since 2×21380163² = 914222739813138, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21380113) 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 15 ways as a sum of consecutive naturals, for example, 16945 + ... + 18162.

It is an arithmetic number, because the mean of its divisors is an integer number (2106480).

Almost surely, 2^21380163 is an apocalyptic number.

21380163 is a deficient number, since it is larger than the sum of its proper divisors (12323517).

21380163 is a wasteful number, since it uses less digits than its factorization.

21380163 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35146.

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 21380163 is about 4623.8688346449. The cubic root of 21380163 is about 277.5472981630.

Adding to 21380163 its reverse (36108312), we get a palindrome (57488475).

The spelling of 21380163 in words is "twenty-one million, three hundred eighty thousand, one hundred sixty-three".