20880000 has 240 divisors, whose sum is σ = 77670450. Its totient is φ = 5376000.

The previous prime is 20879977. The next prime is 20880001. The reversal of 20880000 is 8802.

It can be written as a sum of positive squares in 5 ways, for example, as 304704 + 20575296 = 552^2 + 4536^2 .

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is not an unprimeable number, because it can be changed into a prime (20880001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 719986 + ... + 720014.

Almost surely, 2^20880000 is an apocalyptic number.

20880000 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 20880000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38835225).

20880000 is an abundant number, since it is smaller than the sum of its proper divisors (56790450).

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

20880000 is an equidigital number, since it uses as much as digits as its factorization.

20880000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69 (or 39 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 20880000 is about 4569.4638635183. The cubic root of 20880000 is about 275.3659041111.

Adding to 20880000 its reverse (8802), we get a palindrome (20888802).

It can be divided in two parts, 208 and 80000, that added together give a palindrome (80208).

The spelling of 20880000 in words is "twenty million, eight hundred eighty thousand".