21949439 has 8 divisors (see below), whose sum is σ = 22440000. Its totient is φ = 21464352.

The previous prime is 21949409. The next prime is 21949453. The reversal of 21949439 is 93494912.

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

It is a cyclic number.

It is not a de Polignac number, because 21949439 - 2⁸ = 21949183 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21949396 and 21949405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21949409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7337 + ... + 9885.

It is an arithmetic number, because the mean of its divisors is an integer number (2805000).

Almost surely, 2^21949439 is an apocalyptic number.

21949439 is a deficient number, since it is larger than the sum of its proper divisors (490561).

21949439 is a wasteful number, since it uses less digits than its factorization.

21949439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2737.

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

The square root of 21949439 is about 4685.0228387917. The cubic root of 21949439 is about 279.9891109711.

The spelling of 21949439 in words is "twenty-one million, nine hundred forty-nine thousand, four hundred thirty-nine".