216309545 has 8 divisors (see below), whose sum is σ = 259708680. Its totient is φ = 172956160.

The previous prime is 216309539. The next prime is 216309551. The reversal of 216309545 is 545903612.

It is an interprime number because it is at equal distance from previous prime (216309539) and next prime (216309551).

It can be written as a sum of positive squares in 4 ways, for example, as 45954841 + 170354704 = 6779^2 + 13052^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 216309545 - 2⁴ = 216309529 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11 + ... + 20799.

It is an arithmetic number, because the mean of its divisors is an integer number (32463585).

Almost surely, 2^216309545 is an apocalyptic number.

It is an amenable number.

216309545 is a deficient number, since it is larger than the sum of its proper divisors (43399135).

216309545 is a wasteful number, since it uses less digits than its factorization.

216309545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22875.

The product of its (nonzero) digits is 32400, while the sum is 35.

The square root of 216309545 is about 14707.4656212415. The cubic root of 216309545 is about 600.2864789353.

The spelling of 216309545 in words is "two hundred sixteen million, three hundred nine thousand, five hundred forty-five".