20390560 has 48 divisors (see below), whose sum is σ = 49738752. Its totient is φ = 7891200.

The previous prime is 20390549. The next prime is 20390569. The reversal of 20390560 is 6509302.

It is a super-2 number, since 2×20390560² = 831549874227200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20390569) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2905 + ... + 7015.

It is an arithmetic number, because the mean of its divisors is an integer number (1036224).

Almost surely, 2^20390560 is an apocalyptic number.

20390560 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 20390560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24869376).

20390560 is an abundant number, since it is smaller than the sum of its proper divisors (29348192).

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

20390560 is a wasteful number, since it uses less digits than its factorization.

20390560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4157 (or 4149 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 25.

The square root of 20390560 is about 4515.5907697665. The cubic root of 20390560 is about 273.1972883693.

Adding to 20390560 its reverse (6509302), we get a palindrome (26899862).

The spelling of 20390560 in words is "twenty million, three hundred ninety thousand, five hundred sixty".