20139588 has 90 divisors (see below), whose sum is σ = 59644494. Its totient is φ = 5729472.

The previous prime is 20139583. The next prime is 20139589. The reversal of 20139588 is 88593102.

It can be written as a sum of positive squares in only one way, i.e., 14607684 + 5531904 = 3822^2 + 2352^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (20139583) 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 29 ways as a sum of consecutive naturals, for example, 86320 + ... + 86552.

Almost surely, 2^20139588 is an apocalyptic number.

20139588 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20139588, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29822247).

20139588 is an abundant number, since it is smaller than the sum of its proper divisors (39504906).

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

20139588 is a wasteful number, since it uses less digits than its factorization.

20139588 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 271 (or 245 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 20139588 is about 4487.7152316073. The cubic root of 20139588 is about 272.0717983760.

The spelling of 20139588 in words is "twenty million, one hundred thirty-nine thousand, five hundred eighty-eight".