20321880 has 128 divisors (see below), whose sum is σ = 65664000. Its totient is φ = 5018112.

The previous prime is 20321879. The next prime is 20321893. The reversal of 20321880 is 8812302.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 20321880.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 102021 + ... + 102219.

It is an arithmetic number, because the mean of its divisors is an integer number (513000).

Almost surely, 2^20321880 is an apocalyptic number.

20321880 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 20321880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32832000).

20321880 is an abundant number, since it is smaller than the sum of its proper divisors (45342120).

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

20321880 is a wasteful number, since it uses less digits than its factorization.

20321880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 273 (or 269 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 24.

The square root of 20321880 is about 4507.9795917905. The cubic root of 20321880 is about 272.8902133390.

The spelling of 20321880 in words is "twenty million, three hundred twenty-one thousand, eight hundred eighty".