20939520 has 288 divisors, whose sum is σ = 82414080. Its totient is φ = 4423680.

The previous prime is 20939519. The next prime is 20939543. The reversal of 20939520 is 2593902.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 510700 + ... + 510740.

It is an arithmetic number, because the mean of its divisors is an integer number (286160).

Almost surely, 2^20939520 is an apocalyptic number.

20939520 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 20939520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41207040).

20939520 is an abundant number, since it is smaller than the sum of its proper divisors (61474560).

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

20939520 is a wasteful number, since it uses less digits than its factorization.

20939520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91 (or 77 counting only the distinct ones).

The product of its (nonzero) digits is 4860, while the sum is 30.

The square root of 20939520 is about 4575.9720278865. The cubic root of 20939520 is about 275.6273062471.

The spelling of 20939520 in words is "twenty million, nine hundred thirty-nine thousand, five hundred twenty".