216645345 has 48 divisors (see below), whose sum is σ = 436475520. Its totient is φ = 97350912.

The previous prime is 216645307. The next prime is 216645409. The reversal of 216645345 is 543546612.

216645345 is a `hidden beast` number, since 2 + 1 + 6 + 645 + 3 + 4 + 5 = 666.

It is not a de Polignac number, because 216645345 - 2¹⁸ = 216383201 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 12757 + ... + 24413.

It is an arithmetic number, because the mean of its divisors is an integer number (9093240).

Almost surely, 2^216645345 is an apocalyptic number.

It is an amenable number.

216645345 is an abundant number, since it is smaller than the sum of its proper divisors (219830175).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

216645345 is a wasteful number, since it uses less digits than its factorization.

216645345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11734 (or 11731 counting only the distinct ones).

The product of its digits is 86400, while the sum is 36.

The square root of 216645345 is about 14718.8771650558. The cubic root of 216645345 is about 600.5969475591.

The spelling of 216645345 in words is "two hundred sixteen million, six hundred forty-five thousand, three hundred forty-five".