216555117 has 16 divisors (see below), whose sum is σ = 298388160. Its totient is φ = 139594752.

The previous prime is 216555107. The next prime is 216555127. The reversal of 216555117 is 711555612.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (216555107) and next prime (216555127).

It is not a de Polignac number, because 216555117 - 2¹² = 216551021 is a prime.

It is a super-2 number, since 2×216555117² = 93792237397767378, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216555107) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12109 + ... + 24077.

It is an arithmetic number, because the mean of its divisors is an integer number (18649260).

Almost surely, 2^216555117 is an apocalyptic number.

It is an amenable number.

216555117 is a deficient number, since it is larger than the sum of its proper divisors (81833043).

216555117 is a wasteful number, since it uses less digits than its factorization.

216555117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12172.

The product of its digits is 10500, while the sum is 33.

The square root of 216555117 is about 14715.8118022758. The cubic root of 216555117 is about 600.5135575279.

The spelling of 216555117 in words is "two hundred sixteen million, five hundred fifty-five thousand, one hundred seventeen".