20828880 has 80 divisors (see below), whose sum is σ = 71751360. Its totient is φ = 5553792.

The previous prime is 20828879. The next prime is 20828897. The reversal of 20828880 is 8882802.

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 (36).

It is a congruent number.

It is an unprimeable number.

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, 2662 + ... + 6981.

It is an arithmetic number, because the mean of its divisors is an integer number (896892).

Almost surely, 2^20828880 is an apocalyptic number.

20828880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20828880 is an abundant number, since it is smaller than the sum of its proper divisors (50922480).

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

20828880 is a wasteful number, since it uses less digits than its factorization.

20828880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9665 (or 9653 counting only the distinct ones).

The product of its (nonzero) digits is 16384, while the sum is 36.

The square root of 20828880 is about 4563.8667815790. The cubic root of 20828880 is about 275.1409965671.

The spelling of 20828880 in words is "twenty million, eight hundred twenty-eight thousand, eight hundred eighty".