21206150784 has 256 divisors, whose sum is σ = 77032032000. Its totient is φ = 5592748032.

The previous prime is 21206150783. The next prime is 21206150803. The reversal of 21206150784 is 48705160212.

21206150784 is a `hidden beast` number, since 2 + 12 + 0 + 61 + 507 + 84 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (21206150783) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 280782 + ... + 348210.

It is an arithmetic number, because the mean of its divisors is an integer number (300906375).

Almost surely, 2^21206150784 is an apocalyptic number.

21206150784 is a gapful number since it is divisible by the number (24) 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 21206150784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38516016000).

21206150784 is an abundant number, since it is smaller than the sum of its proper divisors (55825881216).

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

21206150784 is a wasteful number, since it uses less digits than its factorization.

21206150784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67472 (or 67454 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 36.

The spelling of 21206150784 in words is "twenty-one billion, two hundred six million, one hundred fifty thousand, seven hundred eighty-four".