20320400320 has 224 divisors, whose sum is σ = 54639277056. Its totient is φ = 7133798400.

The previous prime is 20320400293. The next prime is 20320400411. The reversal of 20320400320 is 2300402302.

It is a super-2 number, since 2×20320400320² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a junction number, because it is equal to n+sod(n) for n = 20320400294 and 20320400303.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 14864277 + ... + 14865643.

It is an arithmetic number, because the mean of its divisors is an integer number (243925344).

Almost surely, 2^20320400320 is an apocalyptic number.

20320400320 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 20320400320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27319638528).

20320400320 is an abundant number, since it is smaller than the sum of its proper divisors (34318876736).

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

20320400320 is a wasteful number, since it uses less digits than its factorization.

20320400320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1539 (or 1529 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 16.

Adding to 20320400320 its reverse (2300402302), we get a palindrome (22620802622).

The spelling of 20320400320 in words is "twenty billion, three hundred twenty million, four hundred thousand, three hundred twenty".