216520066605605 has 16 divisors (see below), whose sum is σ = 296942107365120. Its totient is φ = 148470751948032.

The previous prime is 216520066605593. The next prime is 216520066605709. The reversal of 216520066605605 is 506506660025612.

It is a cyclic number.

It is not a de Polignac number, because 216520066605605 - 2³⁴ = 216502886736421 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40218656 + ... + 45283334.

It is an arithmetic number, because the mean of its divisors is an integer number (18558881710320).

Almost surely, 2^{216520066605605} is an apocalyptic number.

It is an amenable number.

216520066605605 is a deficient number, since it is larger than the sum of its proper divisors (80422040759515).

216520066605605 is a wasteful number, since it uses less digits than its factorization.

216520066605605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6286148.

The product of its (nonzero) digits is 3888000, while the sum is 50.

The spelling of 216520066605605 in words is "two hundred sixteen trillion, five hundred twenty billion, sixty-six million, six hundred five thousand, six hundred five".