21440899 has 6 divisors (see below), whose sum is σ = 22414196. Its totient is φ = 20508180.

The previous prime is 21440891. The next prime is 21440917. The reversal of 21440899 is 99804412.

It is a happy number.

It is not a de Polignac number, because 21440899 - 2³ = 21440891 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21440891) 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 5 ways as a sum of consecutive naturals, for example, 19737 + ... + 20794.

Almost surely, 2^21440899 is an apocalyptic number.

21440899 is a deficient number, since it is larger than the sum of its proper divisors (973297).

21440899 is an equidigital number, since it uses as much as digits as its factorization.

21440899 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40577 (or 40554 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 21440899 is about 4630.4318373128. The cubic root of 21440899 is about 277.8098651585.

The spelling of 21440899 in words is "twenty-one million, four hundred forty thousand, eight hundred ninety-nine".