216090945 has 24 divisors (see below), whose sum is σ = 428066496. Its totient is φ = 98784288.

The previous prime is 216090943. The next prime is 216090947. The reversal of 216090945 is 549090612.

216090945 is a `hidden beast` number, since 2 + 1 + 609 + 0 + 9 + 45 = 666.

It is an interprime number because it is at equal distance from previous prime (216090943) and next prime (216090947).

It is not a de Polignac number, because 216090945 - 2¹ = 216090943 is a prime.

It is not an unprimeable number, because it can be changed into a prime (216090943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 342687 + ... + 343316.

It is an arithmetic number, because the mean of its divisors is an integer number (17836104).

Almost surely, 2^216090945 is an apocalyptic number.

It is an amenable number.

216090945 is a deficient number, since it is larger than the sum of its proper divisors (211975551).

216090945 is a wasteful number, since it uses less digits than its factorization.

216090945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 686021 (or 686018 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 216090945 is about 14700.0321428220. The cubic root of 216090945 is about 600.0841965177.

The spelling of 216090945 in words is "two hundred sixteen million, ninety thousand, nine hundred forty-five".