216247691 has 12 divisors (see below), whose sum is σ = 238771176. Its totient is φ = 195697920.

The previous prime is 216247673. The next prime is 216247697. The reversal of 216247691 is 196742612.

It is not a de Polignac number, because 216247691 - 2¹⁴ = 216231307 is a prime.

It is a hoax number, since the sum of its digits (38) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216247697) 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, 23531 + ... + 31403.

It is an arithmetic number, because the mean of its divisors is an integer number (19897598).

Almost surely, 2^216247691 is an apocalyptic number.

216247691 is a deficient number, since it is larger than the sum of its proper divisors (22523485).

216247691 is a wasteful number, since it uses less digits than its factorization.

216247691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8122 (or 8111 counting only the distinct ones).

The product of its digits is 36288, while the sum is 38.

The square root of 216247691 is about 14705.3626612879. The cubic root of 216247691 is about 600.2292559102.

The spelling of 216247691 in words is "two hundred sixteen million, two hundred forty-seven thousand, six hundred ninety-one".