215788066555 has 4 divisors (see below), whose sum is σ = 258945679872. Its totient is φ = 172630453240.

The previous prime is 215788066531. The next prime is 215788066631. The reversal of 215788066555 is 555660887512.

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

It is not a de Polignac number, because 215788066555 - 2¹⁵ = 215788033787 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 215788066555.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21578806651 + ... + 21578806660.

It is an arithmetic number, because the mean of its divisors is an integer number (64736419968).

Almost surely, 2^215788066555 is an apocalyptic number.

215788066555 is a deficient number, since it is larger than the sum of its proper divisors (43157613317).

215788066555 is an equidigital number, since it uses as much as digits as its factorization.

215788066555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43157613316.

The product of its (nonzero) digits is 20160000, while the sum is 58.

The spelling of 215788066555 in words is "two hundred fifteen billion, seven hundred eighty-eight million, sixty-six thousand, five hundred fifty-five".