20321868 has 144 divisors (see below), whose sum is σ = 62052480. Its totient is φ = 5128704.

The previous prime is 20321867. The next prime is 20321869. The reversal of 20321868 is 86812302.

It is an interprime number because it is at equal distance from previous prime (20321867) and next prime (20321869).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20321867) 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 47 ways as a sum of consecutive naturals, for example, 189871 + ... + 189977.

It is an arithmetic number, because the mean of its divisors is an integer number (430920).

Almost surely, 2^20321868 is an apocalyptic number.

20321868 is a gapful number since it is divisible by the number (28) 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 20321868, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31026240).

20321868 is an abundant number, since it is smaller than the sum of its proper divisors (41730612).

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

20321868 is a wasteful number, since it uses less digits than its factorization.

20321868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164 (or 155 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 20321868 is about 4507.9782608171. The cubic root of 20321868 is about 272.8901596254.

The spelling of 20321868 in words is "twenty million, three hundred twenty-one thousand, eight hundred sixty-eight".