217712421394 has 32 divisors (see below), whose sum is σ = 354539928960. Its totient is φ = 99669366912.

The previous prime is 217712421379. The next prime is 217712421497. The reversal of 217712421394 is 493124217712.

It is a self number, because there is not a number n which added to its sum of digits gives 217712421394.

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, 4546227 + ... + 4593865.

It is an arithmetic number, because the mean of its divisors is an integer number (11079372780).

Almost surely, 2^217712421394 is an apocalyptic number.

217712421394 is a deficient number, since it is larger than the sum of its proper divisors (136827507566).

217712421394 is a wasteful number, since it uses less digits than its factorization.

217712421394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49074.

The product of its digits is 169344, while the sum is 43.

The spelling of 217712421394 in words is "two hundred seventeen billion, seven hundred twelve million, four hundred twenty-one thousand, three hundred ninety-four".