21000221785350 has 960 divisors, whose sum is σ = 62199698964480. Its totient is φ = 5247941529600.

The previous prime is 21000221785337. The next prime is 21000221785423. The reversal of 21000221785350 is 5358712200012.

21000221785350 is a `hidden beast` number, since 2 + 1 + 0 + 0 + 0 + 221 + 7 + 85 + 350 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 479 ways as a sum of consecutive naturals, for example, 125749830967 + ... + 125749831133.

It is an arithmetic number, because the mean of its divisors is an integer number (64791353088).

Almost surely, 2^{21000221785350} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21000221785350, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31099849482240).

21000221785350 is an abundant number, since it is smaller than the sum of its proper divisors (41199477179130).

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

21000221785350 is a wasteful number, since it uses less digits than its factorization.

21000221785350 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 515 (or 501 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 36.

Adding to 21000221785350 its reverse (5358712200012), we get a palindrome (26358933985362).

The spelling of 21000221785350 in words is "twenty-one trillion, two hundred twenty-one million, seven hundred eighty-five thousand, three hundred fifty".