20555321400 has 168 divisors, whose sum is σ = 71654413080. Its totient is φ = 5481380160.

The previous prime is 20555321389. The next prime is 20555321407. The reversal of 20555321400 is 412355502.

It is a happy number.

20555321400 is a `hidden beast` number, since 205 + 5 + 53 + 2 + 1 + 400 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20555321407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 41 ways as a sum of consecutive naturals, for example, 75309 + ... + 216291.

Almost surely, 2^20555321400 is an apocalyptic number.

20555321400 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 20555321400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35827206540).

20555321400 is an abundant number, since it is smaller than the sum of its proper divisors (51099091680).

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

20555321400 is a wasteful number, since it uses less digits than its factorization.

20555321400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141017 (or 140993 counting only the distinct ones).

The product of its (nonzero) digits is 6000, while the sum is 27.

Adding to 20555321400 its reverse (412355502), we get a palindrome (20967676902).

The spelling of 20555321400 in words is "twenty billion, five hundred fifty-five million, three hundred twenty-one thousand, four hundred".