20445560 has 64 divisors (see below), whose sum is σ = 49338720. Its totient is φ = 7598080.

The previous prime is 20445541. The next prime is 20445583. The reversal of 20445560 is 6554402.

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, 72620 + ... + 72900.

Almost surely, 2^20445560 is an apocalyptic number.

20445560 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 20445560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24669360).

20445560 is an abundant number, since it is smaller than the sum of its proper divisors (28893160).

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

20445560 is a wasteful number, since it uses less digits than its factorization.

20445560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 416 (or 412 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 26.

The square root of 20445560 is about 4521.6766801708. The cubic root of 20445560 is about 273.4427019527.

Adding to 20445560 its reverse (6554402), we get a palindrome (26999962).

The spelling of 20445560 in words is "twenty million, four hundred forty-five thousand, five hundred sixty".