21280795 has 4 divisors (see below), whose sum is σ = 25536960. Its totient is φ = 17024632.

The previous prime is 21280793. The next prime is 21280807. The reversal of 21280795 is 59708212.

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

It is a cyclic number.

It is not a de Polignac number, because 21280795 - 2¹ = 21280793 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21280795.

It is not an unprimeable number, because it can be changed into a prime (21280793) 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 3 ways as a sum of consecutive naturals, for example, 2128075 + ... + 2128084.

It is an arithmetic number, because the mean of its divisors is an integer number (6384240).

Almost surely, 2^21280795 is an apocalyptic number.

21280795 is a deficient number, since it is larger than the sum of its proper divisors (4256165).

21280795 is an equidigital number, since it uses as much as digits as its factorization.

21280795 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4256164.

The product of its (nonzero) digits is 10080, while the sum is 34.

The square root of 21280795 is about 4613.1112061168. Note that the first 3 decimals coincide. The cubic root of 21280795 is about 277.1166472969.

The spelling of 21280795 in words is "twenty-one million, two hundred eighty thousand, seven hundred ninety-five".