20984560 has 40 divisors (see below), whose sum is σ = 49836096. Its totient is φ = 8213760.

The previous prime is 20984503. The next prime is 20984581. The reversal of 20984560 is 6548902.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 970 + ... + 6550.

Almost surely, 2^20984560 is an apocalyptic number.

20984560 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 20984560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24918048).

20984560 is an abundant number, since it is smaller than the sum of its proper divisors (28851536).

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

20984560 is a wasteful number, since it uses less digits than its factorization.

20984560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5641 (or 5635 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 20984560 is about 4580.8907430761. The cubic root of 20984560 is about 275.8247855216.

The spelling of 20984560 in words is "twenty million, nine hundred eighty-four thousand, five hundred sixty".