20885520 has 80 divisors (see below), whose sum is σ = 68567040. Its totient is φ = 5240832.

The previous prime is 20885509. The next prime is 20885533. The reversal of 20885520 is 2558802.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (30).

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, 1521 + ... + 6639.

It is an arithmetic number, because the mean of its divisors is an integer number (857088).

Almost surely, 2^20885520 is an apocalyptic number.

20885520 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 20885520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34283520).

20885520 is an abundant number, since it is smaller than the sum of its proper divisors (47681520).

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

20885520 is a wasteful number, since it uses less digits than its factorization.

20885520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5152 (or 5146 counting only the distinct ones).

The product of its (nonzero) digits is 6400, while the sum is 30.

The square root of 20885520 is about 4570.0678331946. The cubic root of 20885520 is about 275.3901679340.

The spelling of 20885520 in words is "twenty million, eight hundred eighty-five thousand, five hundred twenty".