216205615 has 16 divisors (see below), whose sum is σ = 267471360. Its totient is φ = 167650560.

The previous prime is 216205573. The next prime is 216205631. The reversal of 216205615 is 516502612.

216205615 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

216205615 is a nontrivial binomial coefficient, being equal to C(20795, 2).

It is not a de Polignac number, because 216205615 - 2⁹ = 216205103 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, 49906 + ... + 54064.

It is an arithmetic number, because the mean of its divisors is an integer number (16716960).

Almost surely, 2^216205615 is an apocalyptic number.

216205615 is the 20794-th triangular number.

216205615 is the 6932-nd centered nonagonal number.

216205615 is a deficient number, since it is larger than the sum of its proper divisors (51265745).

216205615 is a wasteful number, since it uses less digits than its factorization.

216205615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4482.

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 216205615 is about 14703.9319571331. The cubic root of 216205615 is about 600.1903238809.

The spelling of 216205615 in words is "two hundred sixteen million, two hundred five thousand, six hundred fifteen".