21067864786440 has 192 divisors, whose sum is σ = 72123980385600. Its totient is φ = 5318737344000.

The previous prime is 21067864786429. The next prime is 21067864786477. The reversal of 21067864786440 is 4468746876012.

21067864786440 is a `hidden beast` number, since 2 + 1 + 0 + 6 + 78 + 6 + 47 + 86 + 440 = 666.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 8863470 + ... + 10986210.

It is an arithmetic number, because the mean of its divisors is an integer number (375645731175).

Almost surely, 2^{21067864786440} is an apocalyptic number.

21067864786440 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 21067864786440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36061990192800).

21067864786440 is an abundant number, since it is smaller than the sum of its proper divisors (51056115599160).

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

21067864786440 is a wasteful number, since it uses less digits than its factorization.

21067864786440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2124228 (or 2124221 counting only the distinct ones).

The product of its (nonzero) digits is 86704128, while the sum is 63.

The spelling of 21067864786440 in words is "twenty-one trillion, sixty-seven billion, eight hundred sixty-four million, seven hundred eighty-six thousand, four hundred forty".