21355636780800 has 2160 divisors, whose sum is σ = 96315246818560. Its totient is φ = 4559955886080.

The previous prime is 21355636780763. The next prime is 21355636780847. The reversal of 21355636780800 is 808763655312.

21355636780800 is a `hidden beast` number, since 2 + 1 + 3 + 5 + 563 + 6 + 78 + 0 + 8 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (2160).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 5033143479 + ... + 5033147721.

Almost surely, 2^{21355636780800} is an apocalyptic number.

21355636780800 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 21355636780800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48157623409280).

21355636780800 is an abundant number, since it is smaller than the sum of its proper divisors (74959610037760).

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

21355636780800 is a wasteful number, since it uses less digits than its factorization.

21355636780800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4380 (or 4352 counting only the distinct ones).

The product of its (nonzero) digits is 7257600, while the sum is 54.

The spelling of 21355636780800 in words is "twenty-one trillion, three hundred fifty-five billion, six hundred thirty-six million, seven hundred eighty thousand, eight hundred".