20320217400 has 192 divisors, whose sum is σ = 72059316480. Its totient is φ = 4640256000.

The previous prime is 20320217387. The next prime is 20320217431. The reversal of 20320217400 is 471202302.

It is a Cunningham number, because it is equal to 142549²-1.

It is a super-2 number, since 2×20320217400² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7125975 + ... + 7128825.

It is an arithmetic number, because the mean of its divisors is an integer number (375308940).

Almost surely, 2^20320217400 is an apocalyptic number.

20320217400 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 20320217400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36029658240).

20320217400 is an abundant number, since it is smaller than the sum of its proper divisors (51739099080).

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

20320217400 is a wasteful number, since it uses less digits than its factorization.

20320217400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4574 (or 4565 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 21.

Adding to 20320217400 its reverse (471202302), we get a palindrome (20791419702).

The spelling of 20320217400 in words is "twenty billion, three hundred twenty million, two hundred seventeen thousand, four hundred".