216617940 has 144 divisors (see below), whose sum is σ = 819262080. Its totient is φ = 45008640.

The previous prime is 216617939. The next prime is 216617957. The reversal of 216617940 is 49716612.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 216617895 and 216617904.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6046 + ... + 21674.

It is an arithmetic number, because the mean of its divisors is an integer number (5689320).

Almost surely, 2^216617940 is an apocalyptic number.

216617940 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 216617940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (409631040).

216617940 is an abundant number, since it is smaller than the sum of its proper divisors (602644140).

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

216617940 is a wasteful number, since it uses less digits than its factorization.

216617940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15662 (or 15657 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 216617940 is about 14717.9461882424. The cubic root of 216617940 is about 600.5716219077.

The spelling of 216617940 in words is "two hundred sixteen million, six hundred seventeen thousand, nine hundred forty".