216403596865 has 16 divisors (see below), whose sum is σ = 274971455568. Its totient is φ = 162932310016.

The previous prime is 216403596823. The next prime is 216403596881. The reversal of 216403596865 is 568695304612.

It is a Cunningham number, because it is equal to 465192²+1.

It can be written as a sum of positive squares in 8 ways, for example, as 1351591696 + 215052005169 = 36764^2 + 463737^2 .

It is a cyclic number.

It is not a de Polignac number, because 216403596865 - 2¹⁷ = 216403465793 is a prime.

It is a super-2 number, since 2×216403596865² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2972439 + ... + 3044371.

It is an arithmetic number, because the mean of its divisors is an integer number (17185715973).

Almost surely, 2^216403596865 is an apocalyptic number.

It is an amenable number.

216403596865 is a deficient number, since it is larger than the sum of its proper divisors (58567858703).

216403596865 is a wasteful number, since it uses less digits than its factorization.

216403596865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107348.

The product of its (nonzero) digits is 9331200, while the sum is 55.

The spelling of 216403596865 in words is "two hundred sixteen billion, four hundred three million, five hundred ninety-six thousand, eight hundred sixty-five".