21895449 has 4 divisors (see below), whose sum is σ = 29193936. Its totient is φ = 14596964.

The previous prime is 21895421. The next prime is 21895451. The reversal of 21895449 is 94459812.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21895449 - 2²¹ = 19798297 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21895449.

It is not an unprimeable number, because it can be changed into a prime (21895409) 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, 3649239 + ... + 3649244.

It is an arithmetic number, because the mean of its divisors is an integer number (7298484).

Almost surely, 2^21895449 is an apocalyptic number.

It is an amenable number.

21895449 is a deficient number, since it is larger than the sum of its proper divisors (7298487).

21895449 is an equidigital number, since it uses as much as digits as its factorization.

21895449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7298486.

The product of its digits is 103680, while the sum is 42.

The square root of 21895449 is about 4679.2573128649. The cubic root of 21895449 is about 279.7593553131.

The spelling of 21895449 in words is "twenty-one million, eight hundred ninety-five thousand, four hundred forty-nine".