21339789 has 8 divisors (see below), whose sum is σ = 28500672. Its totient is φ = 14202720.

The previous prime is 21339781. The next prime is 21339809. The reversal of 21339789 is 98793312.

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

It is not a de Polignac number, because 21339789 - 2³ = 21339781 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21339789.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21339781) 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, 3744 + ... + 7529.

It is an arithmetic number, because the mean of its divisors is an integer number (3562584).

Almost surely, 2^21339789 is an apocalyptic number.

It is an amenable number.

21339789 is a deficient number, since it is larger than the sum of its proper divisors (7160883).

21339789 is a wasteful number, since it uses less digits than its factorization.

21339789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11907.

The product of its digits is 81648, while the sum is 42.

The square root of 21339789 is about 4619.5009470721. The cubic root of 21339789 is about 277.3724826017.

The spelling of 21339789 in words is "twenty-one million, three hundred thirty-nine thousand, seven hundred eighty-nine".