216380655 has 12 divisors (see below), whose sum is σ = 375059880. Its totient is φ = 115402992.

The previous prime is 216380639. The next prime is 216380669. The reversal of 216380655 is 556083612.

216380655 is a `hidden beast` number, since 216 + 380 + 65 + 5 = 666.

It is not a de Polignac number, because 216380655 - 2⁴ = 216380639 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2404185 + ... + 2404274.

It is an arithmetic number, because the mean of its divisors is an integer number (31254990).

Almost surely, 2^216380655 is an apocalyptic number.

216380655 is a deficient number, since it is larger than the sum of its proper divisors (158679225).

216380655 is a wasteful number, since it uses less digits than its factorization.

216380655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4808470 (or 4808467 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The square root of 216380655 is about 14709.8829023211. The cubic root of 216380655 is about 600.3522514910.

It can be divided in two parts, 21 and 6380655, that added together give a square (6380676 = 2526²).

The spelling of 216380655 in words is "two hundred sixteen million, three hundred eighty thousand, six hundred fifty-five".