217938472 has 8 divisors (see below), whose sum is σ = 408634650. Its totient is φ = 108969232.

The previous prime is 217938443. The next prime is 217938481. The reversal of 217938472 is 274839712.

It can be written as a sum of positive squares in only one way, i.e., 143185156 + 74753316 = 11966^2 + 8646^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13621147 + ... + 13621162.

Almost surely, 2^217938472 is an apocalyptic number.

It is an amenable number.

217938472 is a deficient number, since it is larger than the sum of its proper divisors (190696178).

217938472 is a wasteful number, since it uses less digits than its factorization.

217938472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27242315 (or 27242311 counting only the distinct ones).

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

The square root of 217938472 is about 14762.7393122008. The cubic root of 217938472 is about 601.7895387601.

The spelling of 217938472 in words is "two hundred seventeen million, nine hundred thirty-eight thousand, four hundred seventy-two".