216561338 has 8 divisors (see below), whose sum is σ = 371248032. Its totient is φ = 92811996.

The previous prime is 216561337. The next prime is 216561341. The reversal of 216561338 is 833165612.

216561338 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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

It is a junction number, because it is equal to n+sod(n) for n = 216561298 and 216561307.

It is not an unprimeable number, because it can be changed into a prime (216561337) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7734320 + ... + 7734347.

It is an arithmetic number, because the mean of its divisors is an integer number (46406004).

Almost surely, 2^216561338 is an apocalyptic number.

216561338 is a deficient number, since it is larger than the sum of its proper divisors (154686694).

216561338 is a wasteful number, since it uses less digits than its factorization.

216561338 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15468676.

The product of its digits is 25920, while the sum is 35.

The square root of 216561338 is about 14716.0231720394. The cubic root of 216561338 is about 600.5193078101.

The spelling of 216561338 in words is "two hundred sixteen million, five hundred sixty-one thousand, three hundred thirty-eight".