216533645 has 4 divisors (see below), whose sum is σ = 259840380. Its totient is φ = 173226912.

The previous prime is 216533617. The next prime is 216533659. The reversal of 216533645 is 546335612.

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 164506276 + 52027369 = 12826^2 + 7213^2 .

It is a cyclic number.

It is not a de Polignac number, because 216533645 - 2⁸ = 216533389 is a prime.

It is a super-3 number, since 3×216533645³ (a number of 26 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21653360 + ... + 21653369.

It is an arithmetic number, because the mean of its divisors is an integer number (64960095).

Almost surely, 2^216533645 is an apocalyptic number.

It is an amenable number.

216533645 is a deficient number, since it is larger than the sum of its proper divisors (43306735).

216533645 is an equidigital number, since it uses as much as digits as its factorization.

216533645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43306734.

The product of its digits is 64800, while the sum is 35.

The square root of 216533645 is about 14715.0822287883. The cubic root of 216533645 is about 600.4937093811.

The spelling of 216533645 in words is "two hundred sixteen million, five hundred thirty-three thousand, six hundred forty-five".