20859421 has 8 divisors (see below), whose sum is σ = 22793184. Its totient is φ = 18931920.

The previous prime is 20859403. The next prime is 20859427. The reversal of 20859421 is 12495802.

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 20859421 - 2⁵ = 20859389 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 (20859427) 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, 7951 + ... + 10243.

It is an arithmetic number, because the mean of its divisors is an integer number (2849148).

Almost surely, 2^20859421 is an apocalyptic number.

It is an amenable number.

20859421 is a deficient number, since it is larger than the sum of its proper divisors (1933763).

20859421 is a wasteful number, since it uses less digits than its factorization.

20859421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3131.

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 20859421 is about 4567.2115125096. The cubic root of 20859421 is about 275.2754089379.

The spelling of 20859421 in words is "twenty million, eight hundred fifty-nine thousand, four hundred twenty-one".