20389590 has 128 divisors (see below), whose sum is σ = 60520320. Its totient is φ = 4852224.

The previous prime is 20389583. The next prime is 20389591. The reversal of 20389590 is 9598302.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20389591) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 129792 + ... + 129948.

It is an arithmetic number, because the mean of its divisors is an integer number (472815).

Almost surely, 2^20389590 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20389590, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30260160).

20389590 is an abundant number, since it is smaller than the sum of its proper divisors (40130730).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20389590 is a wasteful number, since it uses less digits than its factorization.

20389590 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223 (or 217 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 20389590 is about 4515.4833628306. The cubic root of 20389590 is about 273.1929562082.

It can be divided in two parts, 2038 and 9590, that added together give a triangular number (11628 = T₁₅₂).

The spelling of 20389590 in words is "twenty million, three hundred eighty-nine thousand, five hundred ninety".