216567481 has 4 divisors (see below), whose sum is σ = 233226532. Its totient is φ = 199908432.

The previous prime is 216567467. The next prime is 216567499. The reversal of 216567481 is 184765612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 25160256 + 191407225 = 5016^2 + 13835^2 .

It is a cyclic number.

It is not a de Polignac number, because 216567481 - 2⁷ = 216567353 is a prime.

It is a super-2 number, since 2×216567481² = 93802947653370722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216567431) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8329506 + ... + 8329531.

It is an arithmetic number, because the mean of its divisors is an integer number (58306633).

Almost surely, 2^216567481 is an apocalyptic number.

It is an amenable number.

216567481 is a deficient number, since it is larger than the sum of its proper divisors (16659051).

216567481 is a wasteful number, since it uses less digits than its factorization.

216567481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16659050.

The product of its digits is 80640, while the sum is 40.

The square root of 216567481 is about 14716.2318886324. The cubic root of 216567481 is about 600.5249858861.

The spelling of 216567481 in words is "two hundred sixteen million, five hundred sixty-seven thousand, four hundred eighty-one".