20139520 has 40 divisors (see below), whose sum is σ = 48293784. Its totient is φ = 8054784.

The previous prime is 20139517. The next prime is 20139521. The reversal of 20139520 is 2593102.

20139520 is nontrivially palindromic in base 14.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 20139491 and 20139500.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20139521) 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, 1374 + ... + 6493.

Almost surely, 2^20139520 is an apocalyptic number.

20139520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20139520 is an abundant number, since it is smaller than the sum of its proper divisors (28154264).

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

20139520 is an frugal number, since it uses more digits than its factorization.

20139520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7890 (or 7874 counting only the distinct ones).

The product of its (nonzero) digits is 540, while the sum is 22.

The square root of 20139520 is about 4487.7076553626. The cubic root of 20139520 is about 272.0714921648.

The spelling of 20139520 in words is "twenty million, one hundred thirty-nine thousand, five hundred twenty".