216261816 has 32 divisors (see below), whose sum is σ = 559299600. Its totient is φ = 69601280.

The previous prime is 216261803. The next prime is 216261833. The reversal of 216261816 is 618162612.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 154665 + ... + 156056.

Almost surely, 2^216261816 is an apocalyptic number.

It is an amenable number.

216261816 is an abundant number, since it is smaller than the sum of its proper divisors (343037784).

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

216261816 is a wasteful number, since it uses less digits than its factorization.

216261816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310759 (or 310755 counting only the distinct ones).

The product of its digits is 6912, while the sum is 33.

The square root of 216261816 is about 14705.8429204177. The cubic root of 216261816 is about 600.2423243406.

The spelling of 216261816 in words is "two hundred sixteen million, two hundred sixty-one thousand, eight hundred sixteen".