216666260 has 24 divisors (see below), whose sum is σ = 455434056. Its totient is φ = 86583680.

The previous prime is 216666259. The next prime is 216666277. The reversal of 216666260 is 62666612.

It can be written as a sum of positive squares in 4 ways, for example, as 14002564 + 202663696 = 3742^2 + 14236^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 216666260.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19034 + ... + 28206.

It is an arithmetic number, because the mean of its divisors is an integer number (18976419).

Almost surely, 2^216666260 is an apocalyptic number.

216666260 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

216666260 is an abundant number, since it is smaller than the sum of its proper divisors (238767796).

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

216666260 is a wasteful number, since it uses less digits than its factorization.

216666260 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10363 (or 10361 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 35.

The square root of 216666260 is about 14719.5876300934. The cubic root of 216666260 is about 600.6162742009.

The spelling of 216666260 in words is "two hundred sixteen million, six hundred sixty-six thousand, two hundred sixty".