20139560 has 64 divisors (see below), whose sum is σ = 54846720. Its totient is φ = 6497280.

The previous prime is 20139557. The next prime is 20139583. The reversal of 20139560 is 6593102.

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, 2645 + ... + 6875.

It is an arithmetic number, because the mean of its divisors is an integer number (856980).

Almost surely, 2^20139560 is an apocalyptic number.

20139560 is a gapful number since it is divisible by the number (20) 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 20139560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27423360).

20139560 is an abundant number, since it is smaller than the sum of its proper divisors (34707160).

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

20139560 is a wasteful number, since it uses less digits than its factorization.

20139560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4266 (or 4262 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 26.

The square root of 20139560 is about 4487.7121119787. The cubic root of 20139560 is about 272.0716722891.

The spelling of 20139560 in words is "twenty million, one hundred thirty-nine thousand, five hundred sixty".