20519920 has 20 divisors (see below), whose sum is σ = 47709000. Its totient is φ = 8207936.

The previous prime is 20519911. The next prime is 20519921. The reversal of 20519920 is 2991502.

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20519921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 128170 + ... + 128329.

It is an arithmetic number, because the mean of its divisors is an integer number (2385450).

Almost surely, 2^20519920 is an apocalyptic number.

20519920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20519920 is an abundant number, since it is smaller than the sum of its proper divisors (27189080).

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

20519920 is a wasteful number, since it uses less digits than its factorization.

20519920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 256512 (or 256506 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 28.

The square root of 20519920 is about 4529.8918309381. The cubic root of 20519920 is about 273.7738023409.

The spelling of 20519920 in words is "twenty million, five hundred nineteen thousand, nine hundred twenty".