216242778 has 8 divisors (see below), whose sum is σ = 432485568. Its totient is φ = 72080924.

The previous prime is 216242759. The next prime is 216242791. The reversal of 216242778 is 877242612.

It is a sphenic number, since it is the product of 3 distinct primes.

216242778 is an admirable number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18020226 + ... + 18020237.

It is an arithmetic number, because the mean of its divisors is an integer number (54060696).

Almost surely, 2^216242778 is an apocalyptic number.

216242778 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

216242778 is a wasteful number, since it uses less digits than its factorization.

216242778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36040468.

The product of its digits is 75264, while the sum is 39.

The square root of 216242778 is about 14705.1956124358. The cubic root of 216242778 is about 600.2247102761.

The spelling of 216242778 in words is "two hundred sixteen million, two hundred forty-two thousand, seven hundred seventy-eight".