217941812 has 18 divisors (see below), whose sum is σ = 419223714. Its totient is φ = 99064240.

The previous prime is 217941793. The next prime is 217941817. The reversal of 217941812 is 218149712.

It can be written as a sum of positive squares in only one way, i.e., 202606756 + 15335056 = 14234^2 + 3916^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217941817) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 224663 + ... + 225630.

Almost surely, 2^217941812 is an apocalyptic number.

217941812 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

217941812 is a deficient number, since it is larger than the sum of its proper divisors (201281902).

217941812 is a wasteful number, since it uses less digits than its factorization.

217941812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 450319 (or 450306 counting only the distinct ones).

The product of its digits is 8064, while the sum is 35.

The square root of 217941812 is about 14762.8524344044. The cubic root of 217941812 is about 601.7926129715.

The spelling of 217941812 in words is "two hundred seventeen million, nine hundred forty-one thousand, eight hundred twelve".