21768481673555 has 8 divisors (see below), whose sum is σ = 26122232346000. Its totient is φ = 17414749113696.

The previous prime is 21768481673539. The next prime is 21768481673569. The reversal of 21768481673555 is 55537618486712.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21768481673555 - 2⁴ = 21768481673539 is a prime.

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 7 ways as a sum of consecutive naturals, for example, 1726505 + ... + 6820394.

It is an arithmetic number, because the mean of its divisors is an integer number (3265279043250).

Almost surely, 2^{21768481673555} is an apocalyptic number.

21768481673555 is a deficient number, since it is larger than the sum of its proper divisors (4353750672445).

21768481673555 is an equidigital number, since it uses as much as digits as its factorization.

21768481673555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9056293.

The product of its digits is 338688000, while the sum is 68.

The spelling of 21768481673555 in words is "twenty-one trillion, seven hundred sixty-eight billion, four hundred eighty-one million, six hundred seventy-three thousand, five hundred fifty-five".