20139288 has 64 divisors (see below), whose sum is σ = 57425760. Its totient is φ = 5830656.

The previous prime is 20139277. The next prime is 20139307. The reversal of 20139288 is 88293102.

It is a super-2 number, since 2×20139288² = 811181842293888, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 3406 + ... + 7202.

Almost surely, 2^20139288 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20139288, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28712880).

20139288 is an abundant number, since it is smaller than the sum of its proper divisors (37286472).

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

20139288 is a wasteful number, since it uses less digits than its factorization.

20139288 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3836 (or 3832 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 20139288 is about 4487.6818069021. The cubic root of 20139288 is about 272.0704474390.

The spelling of 20139288 in words is "twenty million, one hundred thirty-nine thousand, two hundred eighty-eight".