216545444 has 6 divisors (see below), whose sum is σ = 378954534. Its totient is φ = 108272720.

The previous prime is 216545443. The next prime is 216545453. The reversal of 216545444 is 444545612.

It can be written as a sum of positive squares in only one way, i.e., 123654400 + 92891044 = 11120^2 + 9638^2 .

It is not an unprimeable number, because it can be changed into a prime (216545443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27068177 + ... + 27068184.

It is an arithmetic number, because the mean of its divisors is an integer number (63159089).

Almost surely, 2^216545444 is an apocalyptic number.

It is an amenable number.

216545444 is a deficient number, since it is larger than the sum of its proper divisors (162409090).

216545444 is a wasteful number, since it uses less digits than its factorization.

216545444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54136365 (or 54136363 counting only the distinct ones).

The product of its digits is 76800, while the sum is 35.

The square root of 216545444 is about 14715.4831385177. The cubic root of 216545444 is about 600.5046162259.

The spelling of 216545444 in words is "two hundred sixteen million, five hundred forty-five thousand, four hundred forty-four".