20355566400 has 1008 divisors, whose sum is σ = 84264398400. Its totient is φ = 4618321920.

The previous prime is 20355566347. The next prime is 20355566401. The reversal of 20355566400 is 466555302.

It is a happy number.

20355566400 is a `hidden beast` number, since 2 + 0 + 3 + 5 + 5 + 5 + 6 + 640 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20355566401) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 209851152 + ... + 209851248.

Almost surely, 2^20355566400 is an apocalyptic number.

20355566400 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 20355566400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42132199200).

20355566400 is an abundant number, since it is smaller than the sum of its proper divisors (63908832000).

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

20355566400 is a wasteful number, since it uses less digits than its factorization.

20355566400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216 (or 198 counting only the distinct ones).

The product of its (nonzero) digits is 108000, while the sum is 36.

The spelling of 20355566400 in words is "twenty billion, three hundred fifty-five million, five hundred sixty-six thousand, four hundred".