216891384 has 32 divisors (see below), whose sum is σ = 570768000. Its totient is φ = 68491872.

The previous prime is 216891379. The next prime is 216891427. The reversal of 216891384 is 483198612.

It is a super-3 number, since 3×216891384³ (a number of 26 digits) contains 333 as substring.

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, 237364 + ... + 238275.

It is an arithmetic number, because the mean of its divisors is an integer number (17836500).

Almost surely, 2^216891384 is an apocalyptic number.

216891384 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

216891384 is an abundant number, since it is smaller than the sum of its proper divisors (353876616).

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

216891384 is a wasteful number, since it uses less digits than its factorization.

216891384 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 475667 (or 475663 counting only the distinct ones).

The product of its digits is 82944, while the sum is 42.

The square root of 216891384 is about 14727.2327339524. The cubic root of 216891384 is about 600.8242227984.

The spelling of 216891384 in words is "two hundred sixteen million, eight hundred ninety-one thousand, three hundred eighty-four".