216480861 has 24 divisors (see below), whose sum is σ = 321430200. Its totient is φ = 140397120.

The previous prime is 216480833. The next prime is 216480881. The reversal of 216480861 is 168084612.

216480861 is a `hidden beast` number, since 2 + 1 + 648 + 0 + 8 + 6 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 95062500 + 121418361 = 9750^2 + 11019^2 .

It is not a de Polignac number, because 216480861 - 2⁵ = 216480829 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216480811) 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, 620115 + ... + 620463.

It is an arithmetic number, because the mean of its divisors is an integer number (13392925).

Almost surely, 2^216480861 is an apocalyptic number.

It is an amenable number.

216480861 is a deficient number, since it is larger than the sum of its proper divisors (104949339).

216480861 is an frugal number, since it uses more digits than its factorization.

216480861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 478 (or 393 counting only the distinct ones).

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

The square root of 216480861 is about 14713.2885854930. The cubic root of 216480861 is about 600.4449116745. Note that the first 3 decimals are identical.

The spelling of 216480861 in words is "two hundred sixteen million, four hundred eighty thousand, eight hundred sixty-one".