216957840 has 240 divisors, whose sum is σ = 766284288. Its totient is φ = 50688000.

The previous prime is 216957823. The next prime is 216957869. The reversal of 216957840 is 48759612.

It is a tau number, because it is divible by the number of its divisors (240).

It is a junction number, because it is equal to n+sod(n) for n = 216957792 and 216957801.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 900120 + ... + 900360.

Almost surely, 2^216957840 is an apocalyptic number.

216957840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 216957840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (383142144).

216957840 is an abundant number, since it is smaller than the sum of its proper divisors (549326448).

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

216957840 is a wasteful number, since it uses less digits than its factorization.

216957840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310 (or 293 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 42.

The square root of 216957840 is about 14729.4887894998. The cubic root of 216957840 is about 600.8855811558.

The spelling of 216957840 in words is "two hundred sixteen million, nine hundred fifty-seven thousand, eight hundred forty".