216821682 has 48 divisors (see below), whose sum is σ = 585703872. Its totient is φ = 56316960.

The previous prime is 216821681. The next prime is 216821687. The reversal of 216821682 is 286128612.

It is not an unprimeable number, because it can be changed into a prime (216821681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 76833 + ... + 79604.

It is an arithmetic number, because the mean of its divisors is an integer number (12202164).

Almost surely, 2^216821682 is an apocalyptic number.

216821682 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

216821682 is an abundant number, since it is smaller than the sum of its proper divisors (368882190).

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

216821682 is a wasteful number, since it uses less digits than its factorization.

216821682 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156463 (or 156460 counting only the distinct ones).

The product of its digits is 18432, while the sum is 36.

The square root of 216821682 is about 14724.8661114456. The cubic root of 216821682 is about 600.7598539637.

The spelling of 216821682 in words is "two hundred sixteen million, eight hundred twenty-one thousand, six hundred eighty-two".