20387920 has 80 divisors (see below), whose sum is σ = 55353600. Its totient is φ = 6980736.

The previous prime is 20387911. The next prime is 20387953. The reversal of 20387920 is 2978302.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27069 + ... + 27811.

It is an arithmetic number, because the mean of its divisors is an integer number (691920).

Almost surely, 2^20387920 is an apocalyptic number.

20387920 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 20387920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27676800).

20387920 is an abundant number, since it is smaller than the sum of its proper divisors (34965680).

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

20387920 is an equidigital number, since it uses as much as digits as its factorization.

20387920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 777 (or 757 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 31.

The square root of 20387920 is about 4515.2984397490. The cubic root of 20387920 is about 273.1854974234.

The spelling of 20387920 in words is "twenty million, three hundred eighty-seven thousand, nine hundred twenty".