218667816 has 64 divisors (see below), whose sum is σ = 614779200. Its totient is φ = 72005184.

The previous prime is 218667809. The next prime is 218667847. The reversal of 218667816 is 618766812.

It is a happy number.

It is a super-2 number, since 2×218667816² = 95631227508419712, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11830 + ... + 24026.

It is an arithmetic number, because the mean of its divisors is an integer number (9605925).

Almost surely, 2^218667816 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 218667816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (307389600).

218667816 is an abundant number, since it is smaller than the sum of its proper divisors (396111384).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

218667816 is a wasteful number, since it uses less digits than its factorization.

218667816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12295 (or 12285 counting only the distinct ones).

The product of its digits is 193536, while the sum is 45.

The square root of 218667816 is about 14787.4208704561. The cubic root of 218667816 is about 602.4600993990.

The spelling of 218667816 in words is "two hundred eighteen million, six hundred sixty-seven thousand, eight hundred sixteen".