20321388 has 48 divisors (see below), whose sum is σ = 53343360. Its totient is φ = 6689232.

The previous prime is 20321387. The next prime is 20321401. The reversal of 20321388 is 88312302.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (20321387) 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, 7831 + ... + 10097.

It is an arithmetic number, because the mean of its divisors is an integer number (1111320).

Almost surely, 2^20321388 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20321388, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26671680).

20321388 is an abundant number, since it is smaller than the sum of its proper divisors (33021972).

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

20321388 is a wasteful number, since it uses less digits than its factorization.

20321388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2363 (or 2355 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 20321388 is about 4507.9250215593. The cubic root of 20321388 is about 272.8880110646. Note that the first 3 decimals are identical.

The spelling of 20321388 in words is "twenty million, three hundred twenty-one thousand, three hundred eighty-eight".