21919449 has 12 divisors (see below), whose sum is σ = 30203088. Its totient is φ = 14139720.

The previous prime is 21919441. The next prime is 21919459. The reversal of 21919449 is 94491912.

It is not a de Polignac number, because 21919449 - 2³ = 21919441 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21919441) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 919 + ... + 6684.

It is an arithmetic number, because the mean of its divisors is an integer number (2516924).

Almost surely, 2^21919449 is an apocalyptic number.

It is an amenable number.

21919449 is a deficient number, since it is larger than the sum of its proper divisors (8283639).

21919449 is an equidigital number, since it uses as much as digits as its factorization.

21919449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7668 (or 7637 counting only the distinct ones).

The product of its digits is 23328, while the sum is 39.

The square root of 21919449 is about 4681.8211200344. The cubic root of 21919449 is about 279.8615344285.

The spelling of 21919449 in words is "twenty-one million, nine hundred nineteen thousand, four hundred forty-nine".