21180893 has 2 divisors, whose sum is σ = 21180894. Its totient is φ = 21180892.

The previous prime is 21180889. The next prime is 21180917. The reversal of 21180893 is 39808112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19598329 + 1582564 = 4427^2 + 1258^2 .

It is a cyclic number.

It is not a de Polignac number, because 21180893 - 2² = 21180889 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21182893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10590446 + 10590447.

It is an arithmetic number, because the mean of its divisors is an integer number (10590447).

Almost surely, 2^21180893 is an apocalyptic number.

It is an amenable number.

21180893 is a deficient number, since it is larger than the sum of its proper divisors (1).

21180893 is an equidigital number, since it uses as much as digits as its factorization.

21180893 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 21180893 is about 4602.2704179568. The cubic root of 21180893 is about 276.6823285919.

The spelling of 21180893 in words is "twenty-one million, one hundred eighty thousand, eight hundred ninety-three".