217438817834 has 32 divisors (see below), whose sum is σ = 384874484736. Its totient is φ = 90159039360.

The previous prime is 217438817779. The next prime is 217438817879. The reversal of 217438817834 is 438718834712.

It is a self number, because there is not a number n which added to its sum of digits gives 217438817834.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1698992 + ... + 1822484.

It is an arithmetic number, because the mean of its divisors is an integer number (12027327648).

Almost surely, 2^217438817834 is an apocalyptic number.

217438817834 is a deficient number, since it is larger than the sum of its proper divisors (167435666902).

217438817834 is a wasteful number, since it uses less digits than its factorization.

217438817834 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127590.

The product of its digits is 7225344, while the sum is 56.

The spelling of 217438817834 in words is "two hundred seventeen billion, four hundred thirty-eight million, eight hundred seventeen thousand, eight hundred thirty-four".