21439353 has 16 divisors (see below), whose sum is σ = 32406080. Its totient is φ = 12498624.

The previous prime is 21439343. The next prime is 21439387. The reversal of 21439353 is 35393412.

It is not a de Polignac number, because 21439353 - 2¹² = 21435257 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21439353.

It is not an unprimeable number, because it can be changed into a prime (21439343) 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 15 ways as a sum of consecutive naturals, for example, 13726 + ... + 15207.

It is an arithmetic number, because the mean of its divisors is an integer number (2025380).

Almost surely, 2^21439353 is an apocalyptic number.

It is an amenable number.

21439353 is a deficient number, since it is larger than the sum of its proper divisors (10966727).

21439353 is a wasteful number, since it uses less digits than its factorization.

21439353 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28968.

The product of its digits is 9720, while the sum is 30.

The square root of 21439353 is about 4630.2648952301. The cubic root of 21439353 is about 277.8031878207.

The spelling of 21439353 in words is "twenty-one million, four hundred thirty-nine thousand, three hundred fifty-three".