21195385 has 4 divisors (see below), whose sum is σ = 25434468. Its totient is φ = 16956304.

The previous prime is 21195371. The next prime is 21195403. The reversal of 21195385 is 58359112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9560464 + 11634921 = 3092^2 + 3411^2 .

It is a cyclic number.

It is not a de Polignac number, because 21195385 - 2⁷ = 21195257 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21195385.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 2119534 + ... + 2119543.

It is an arithmetic number, because the mean of its divisors is an integer number (6358617).

Almost surely, 2^21195385 is an apocalyptic number.

It is an amenable number.

21195385 is a deficient number, since it is larger than the sum of its proper divisors (4239083).

21195385 is an equidigital number, since it uses as much as digits as its factorization.

21195385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4239082.

The product of its digits is 10800, while the sum is 34.

The square root of 21195385 is about 4603.8445890364. The cubic root of 21195385 is about 276.7454163660.

The spelling of 21195385 in words is "twenty-one million, one hundred ninety-five thousand, three hundred eighty-five".