20617980 has 48 divisors (see below), whose sum is σ = 58260384. Its totient is φ = 5447680.

The previous prime is 20617943. The next prime is 20617981. The reversal of 20617980 is 8971602.

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 15 ways as a sum of consecutive naturals, for example, 5260 + ... + 8300.

It is an arithmetic number, because the mean of its divisors is an integer number (1213758).

Almost surely, 2^20617980 is an apocalyptic number.

20617980 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 20617980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29130192).

20617980 is an abundant number, since it is smaller than the sum of its proper divisors (37642404).

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

20617980 is a wasteful number, since it uses less digits than its factorization.

20617980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3166 (or 3164 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 20617980 is about 4540.7025888072. The cubic root of 20617980 is about 274.2092102792.

The spelling of 20617980 in words is "twenty million, six hundred seventeen thousand, nine hundred eighty".