216111556 has 6 divisors (see below), whose sum is σ = 378195230. Its totient is φ = 108055776.

The previous prime is 216111541. The next prime is 216111569. The reversal of 216111556 is 655111612.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 134931456 + 81180100 = 11616^2 + 9010^2 .

It is a super-2 number, since 2×216111556² = 93408409273482272, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27013941 + ... + 27013948.

Almost surely, 2^216111556 is an apocalyptic number.

It is an amenable number.

216111556 is a deficient number, since it is larger than the sum of its proper divisors (162083674).

216111556 is a wasteful number, since it uses less digits than its factorization.

216111556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54027893 (or 54027891 counting only the distinct ones).

The product of its digits is 1800, while the sum is 28.

The square root of 216111556 is about 14700.7331789948. The cubic root of 216111556 is about 600.1032748154.

The spelling of 216111556 in words is "two hundred sixteen million, one hundred eleven thousand, five hundred fifty-six".