20618928 has 80 divisors (see below), whose sum is σ = 64579200. Its totient is φ = 6246720.

The previous prime is 20618903. The next prime is 20618929. The reversal of 20618928 is 82981602.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 20618892 and 20618901.

It is not an unprimeable number, because it can be changed into a prime (20618929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2583 + ... + 6921.

It is an arithmetic number, because the mean of its divisors is an integer number (807240).

Almost surely, 2^20618928 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 20618928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32289600).

20618928 is an abundant number, since it is smaller than the sum of its proper divisors (43960272).

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

20618928 is a wasteful number, since it uses less digits than its factorization.

20618928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4367 (or 4355 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 20618928 is about 4540.8069767388. The cubic root of 20618928 is about 274.2134128627.

The spelling of 20618928 in words is "twenty million, six hundred eighteen thousand, nine hundred twenty-eight".