217045578638 has 16 divisors (see below), whose sum is σ = 374542232064. Its totient is φ = 92403509400.

The previous prime is 217045578611. The next prime is 217045578661. The reversal of 217045578638 is 836875540712.

217045578638 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent 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 7 ways as a sum of consecutive naturals, for example, 51333170 + ... + 51337397.

It is an arithmetic number, because the mean of its divisors is an integer number (23408889504).

Almost surely, 2^217045578638 is an apocalyptic number.

217045578638 is a deficient number, since it is larger than the sum of its proper divisors (157496653426).

217045578638 is a wasteful number, since it uses less digits than its factorization.

217045578638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102670727.

The product of its (nonzero) digits is 11289600, while the sum is 56.

The spelling of 217045578638 in words is "two hundred seventeen billion, forty-five million, five hundred seventy-eight thousand, six hundred thirty-eight".