216683640 has 128 divisors (see below), whose sum is σ = 725716800. Its totient is φ = 57507840.

The previous prime is 216683633. The next prime is 216683659. The reversal of 216683640 is 46386612.

216683640 is a `hidden beast` number, since 2 + 1 + 6 + 6 + 8 + 3 + 640 = 666.

216683640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 = 216683595 and 216683604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 337720 + ... + 338360.

Almost surely, 2^216683640 is an apocalyptic number.

216683640 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 216683640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (362858400).

216683640 is an abundant number, since it is smaller than the sum of its proper divisors (509033160).

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

216683640 is a wasteful number, since it uses less digits than its factorization.

216683640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 974 (or 964 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 216683640 is about 14720.1779880544. The cubic root of 216683640 is about 600.6323333568.

The spelling of 216683640 in words is "two hundred sixteen million, six hundred eighty-three thousand, six hundred forty".