21457795 has 4 divisors (see below), whose sum is σ = 25749360. Its totient is φ = 17166232.

The previous prime is 21457771. The next prime is 21457819. The reversal of 21457795 is 59775412.

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

It is an interprime number because it is at equal distance from previous prime (21457771) and next prime (21457819).

It is a cyclic number.

It is not a de Polignac number, because 21457795 - 2²¹ = 19360643 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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, 2145775 + ... + 2145784.

It is an arithmetic number, because the mean of its divisors is an integer number (6437340).

Almost surely, 2^21457795 is an apocalyptic number.

21457795 is a deficient number, since it is larger than the sum of its proper divisors (4291565).

21457795 is an equidigital number, since it uses as much as digits as its factorization.

21457795 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4291564.

The product of its digits is 88200, while the sum is 40.

The square root of 21457795 is about 4632.2559298899. The cubic root of 21457795 is about 277.8828198584.

The spelling of 21457795 in words is "twenty-one million, four hundred fifty-seven thousand, seven hundred ninety-five".