216117915 has 32 divisors (see below), whose sum is σ = 373101120. Its totient is φ = 106192896.

The previous prime is 216117877. The next prime is 216117917. The reversal of 216117915 is 519711612.

It is not a de Polignac number, because 216117915 - 2¹⁰ = 216116891 is a prime.

It is not an unprimeable number, because it can be changed into a prime (216117917) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 180559 + ... + 181751.

It is an arithmetic number, because the mean of its divisors is an integer number (11659410).

Almost surely, 2^216117915 is an apocalyptic number.

216117915 is a deficient number, since it is larger than the sum of its proper divisors (156983205).

216117915 is a wasteful number, since it uses less digits than its factorization.

216117915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2143.

The product of its digits is 3780, while the sum is 33.

The square root of 216117915 is about 14700.9494591336. The cubic root of 216117915 is about 600.1091606943.

The spelling of 216117915 in words is "two hundred sixteen million, one hundred seventeen thousand, nine hundred fifteen".