20709439 has 8 divisors (see below), whose sum is σ = 21161840. Its totient is φ = 20260800.

The previous prime is 20709433. The next prime is 20709461. The reversal of 20709439 is 93490702.

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 20709439 - 2³ = 20709431 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20709431) 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 7 ways as a sum of consecutive naturals, for example, 12067 + ... + 13675.

It is an arithmetic number, because the mean of its divisors is an integer number (2645230).

Almost surely, 2^20709439 is an apocalyptic number.

20709439 is a deficient number, since it is larger than the sum of its proper divisors (452401).

20709439 is a wasteful number, since it uses less digits than its factorization.

20709439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1881.

The product of its (nonzero) digits is 13608, while the sum is 34.

The square root of 20709439 is about 4550.7624635878. The cubic root of 20709439 is about 274.6140657970.

The spelling of 20709439 in words is "twenty million, seven hundred nine thousand, four hundred thirty-nine".