20321000 has 64 divisors (see below), whose sum is σ = 54362880. Its totient is φ = 6964800.

The previous prime is 20320999. The next prime is 20321003. The reversal of 20321000 is 12302.

It is a Harshad number since it is a multiple of its sum of digits (8).

It is not an unprimeable number, because it can be changed into a prime (20321003) 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 15 ways as a sum of consecutive naturals, for example, 5549 + ... + 8451.

It is an arithmetic number, because the mean of its divisors is an integer number (849420).

Almost surely, 2^20321000 is an apocalyptic number.

20321000 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 20321000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27181440).

20321000 is an abundant number, since it is smaller than the sum of its proper divisors (34041880).

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

20321000 is a wasteful number, since it uses less digits than its factorization.

20321000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2931 (or 2917 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 8.

The square root of 20321000 is about 4507.8819860329. The cubic root of 20321000 is about 272.8862742865.

Adding to 20321000 its reverse (12302), we get a palindrome (20333302).

The spelling of 20321000 in words is "twenty million, three hundred twenty-one thousand".