261216016 has 20 divisors (see below), whose sum is σ = 535877532. Its totient is φ = 122925056.

The previous prime is 261216001. The next prime is 261216017. The reversal of 261216016 is 610612162.

261216016 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 121881600 + 139334416 = 11040^2 + 11804^2 .

It is not an unprimeable number, because it can be changed into a prime (261216017) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 479905 + ... + 480448.

Almost surely, 2^261216016 is an apocalyptic number.

It is an amenable number.

261216016 is an abundant number, since it is smaller than the sum of its proper divisors (274661516).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261216016 is a wasteful number, since it uses less digits than its factorization.

261216016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 960378 (or 960372 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 261216016 is about 16162.1785660226. The cubic root of 261216016 is about 639.2439118059.

Adding to 261216016 its reverse (610612162), we get a palindrome (871828178).

The spelling of 261216016 in words is "two hundred sixty-one million, two hundred sixteen thousand, sixteen".