216544107649 has 9 divisors (see below), whose sum is σ = 218637071107. Its totient is φ = 214471004584.

The previous prime is 216544107617. The next prime is 216544107701. The reversal of 216544107649 is 946701445612.

The square root of 216544107649 is 465343.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 4852097649 + 211692010000 = 69657^2 + 460100^2 .

It is not a de Polignac number, because 216544107649 - 2⁵ = 216544107617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216544107349) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 49789527 + ... + 49793875.

Almost surely, 2^216544107649 is an apocalyptic number.

216544107649 is the 465343-rd square number.

216544107649 is the 232672-nd centered octagonal number.

It is an amenable number.

216544107649 is a deficient number, since it is larger than the sum of its proper divisors (2092963458).

216544107649 is an frugal number, since it uses more digits than its factorization.

216544107649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8912 (or 4456 counting only the distinct ones).

The product of its (nonzero) digits is 1451520, while the sum is 49.

Multiplying 216544107649 by its sum of digits (49), we get a square (10610661274801 = 3257401²).

The spelling of 216544107649 in words is "two hundred sixteen billion, five hundred forty-four million, one hundred seven thousand, six hundred forty-nine".