215545466665 has 4 divisors (see below), whose sum is σ = 258654560004. Its totient is φ = 172436373328.

The previous prime is 215545466659. The next prime is 215545466677. The reversal of 215545466665 is 566664545512.

215545466665 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 142446611241 + 73098855424 = 377421^2 + 270368^2 .

It is a cyclic number.

It is not a de Polignac number, because 215545466665 - 2⁷ = 215545466537 is a prime.

It is a Duffinian number.

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 3 ways as a sum of consecutive naturals, for example, 21554546662 + ... + 21554546671.

It is an arithmetic number, because the mean of its divisors is an integer number (64663640001).

Almost surely, 2^215545466665 is an apocalyptic number.

It is an amenable number.

215545466665 is a deficient number, since it is larger than the sum of its proper divisors (43109093339).

215545466665 is an equidigital number, since it uses as much as digits as its factorization.

215545466665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43109093338.

The product of its digits is 25920000, while the sum is 55.

The spelling of 215545466665 in words is "two hundred fifteen billion, five hundred forty-five million, four hundred sixty-six thousand, six hundred sixty-five".