216649071 has 12 divisors (see below), whose sum is σ = 331345872. Its totient is φ = 135936576.

The previous prime is 216649057. The next prime is 216649087. The reversal of 216649071 is 170946612.

216649071 is a `hidden beast` number, since 2 + 1 + 6 + 649 + 0 + 7 + 1 = 666.

It is not a de Polignac number, because 216649071 - 2¹⁵ = 216616303 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216649021) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 707851 + ... + 708156.

It is an arithmetic number, because the mean of its divisors is an integer number (27612156).

Almost surely, 2^216649071 is an apocalyptic number.

216649071 is a deficient number, since it is larger than the sum of its proper divisors (114696801).

216649071 is a wasteful number, since it uses less digits than its factorization.

216649071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1416030 (or 1416027 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 216649071 is about 14719.0037366664. The cubic root of 216649071 is about 600.6003906847.

The spelling of 216649071 in words is "two hundred sixteen million, six hundred forty-nine thousand, seventy-one".