20859890 has 8 divisors (see below), whose sum is σ = 37547820. Its totient is φ = 8343952.

The previous prime is 20859889. The next prime is 20859893. The reversal of 20859890 is 9895802.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20857489 + 2401 = 4567^2 + 49^2 .

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20859893) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1042985 + ... + 1043004.

Almost surely, 2^20859890 is an apocalyptic number.

20859890 is a deficient number, since it is larger than the sum of its proper divisors (16687930).

20859890 is a wasteful number, since it uses less digits than its factorization.

20859890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2085996.

The product of its (nonzero) digits is 51840, while the sum is 41.

The square root of 20859890 is about 4567.2628564601. The cubic root of 20859890 is about 275.2774720057.

The spelling of 20859890 in words is "twenty million, eight hundred fifty-nine thousand, eight hundred ninety".