209475647855 has 4 divisors (see below), whose sum is σ = 251370777432. Its totient is φ = 167580518280.

The previous prime is 209475647837. The next prime is 209475647893. The reversal of 209475647855 is 558746574902.

209475647855 is digitally balanced in base 11, 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, and also an emirpimes, since its reverse is a distinct semiprime: 558746574902 = 2 ⋅279373287451.

It is not a de Polignac number, because 209475647855 - 2¹⁴ = 209475631471 is a prime.

It is a super-2 number, since 2×209475647855² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

209475647855 is strictly pandigital in base 11.

It is a congruent number.

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, 20947564781 + ... + 20947564790.

It is an arithmetic number, because the mean of its divisors is an integer number (62842694358).

Almost surely, 2^209475647855 is an apocalyptic number.

209475647855 is a deficient number, since it is larger than the sum of its proper divisors (41895129577).

209475647855 is an equidigital number, since it uses as much as digits as its factorization.

209475647855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41895129576.

The product of its (nonzero) digits is 84672000, while the sum is 62.

The spelling of 209475647855 in words is "two hundred nine billion, four hundred seventy-five million, six hundred forty-seven thousand, eight hundred fifty-five".