20617984 has 36 divisors (see below), whose sum is σ = 42135016. Its totient is φ = 10063872.

The previous prime is 20617981. The next prime is 20617999. The reversal of 20617984 is 48971602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20617981) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10072 + ... + 11944.

Almost surely, 2^20617984 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20617984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21067508).

20617984 is an abundant number, since it is smaller than the sum of its proper divisors (21517032).

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

20617984 is an equidigital number, since it uses as much as digits as its factorization.

20617984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1932 (or 1918 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 20617984 is about 4540.7030292676. The cubic root of 20617984 is about 274.2092280119.

The spelling of 20617984 in words is "twenty million, six hundred seventeen thousand, nine hundred eighty-four".