21449939 has 8 divisors (see below), whose sum is σ = 24810240. Its totient is φ = 18163656.

The previous prime is 21449933. The next prime is 21449941. The reversal of 21449939 is 93994412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21449939 - 2¹⁶ = 21384403 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21449896 and 21449905.

It is not an unprimeable number, because it can be changed into a prime (21449933) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 17879 + ... + 19040.

It is an arithmetic number, because the mean of its divisors is an integer number (3101280).

Almost surely, 2^21449939 is an apocalyptic number.

21449939 is a deficient number, since it is larger than the sum of its proper divisors (3360301).

21449939 is an equidigital number, since it uses as much as digits as its factorization.

21449939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37009.

The product of its digits is 69984, while the sum is 41.

The square root of 21449939 is about 4631.4078852979. The cubic root of 21449939 is about 277.8489034517.

The spelling of 21449939 in words is "twenty-one million, four hundred forty-nine thousand, nine hundred thirty-nine".