216945545 has 12 divisors (see below), whose sum is σ = 272148996. Its totient is φ = 166008480.

The previous prime is 216945523. The next prime is 216945571. The reversal of 216945545 is 545549612.

It can be written as a sum of positive squares in 2 ways, for example, as 164121721 + 52823824 = 12811^2 + 7268^2 .

It is not a de Polignac number, because 216945545 - 2⁶ = 216945481 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 38366 + ... + 43655.

It is an arithmetic number, because the mean of its divisors is an integer number (22679083).

Almost surely, 2^216945545 is an apocalyptic number.

It is an amenable number.

216945545 is a deficient number, since it is larger than the sum of its proper divisors (55203451).

216945545 is an equidigital number, since it uses as much as digits as its factorization.

216945545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82072 (or 82049 counting only the distinct ones).

The product of its digits is 216000, while the sum is 41.

The square root of 216945545 is about 14729.0714235487. The cubic root of 216945545 is about 600.8742302135.

The spelling of 216945545 in words is "two hundred sixteen million, nine hundred forty-five thousand, five hundred forty-five".