20859439 has 8 divisors (see below), whose sum is σ = 21780000. Its totient is φ = 19952352.

The previous prime is 20859431. The next prime is 20859451. The reversal of 20859439 is 93495802.

It is a happy number.

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 20859439 - 2³ = 20859431 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 (20859431) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 139 + ... + 6460.

It is an arithmetic number, because the mean of its divisors is an integer number (2722500).

Almost surely, 2^20859439 is an apocalyptic number.

20859439 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

20859439 is a deficient number, since it is larger than the sum of its proper divisors (920561).

20859439 is a wasteful number, since it uses less digits than its factorization.

20859439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6737.

The product of its (nonzero) digits is 77760, while the sum is 40.

The square root of 20859439 is about 4567.2134830770. The cubic root of 20859439 is about 275.2754881181.

The spelling of 20859439 in words is "twenty million, eight hundred fifty-nine thousand, four hundred thirty-nine".