261640916 has 24 divisors (see below), whose sum is σ = 487952640. Its totient is φ = 122468192.

The previous prime is 261640889. The next prime is 261640921. The reversal of 261640916 is 619046162.

261640916 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25931 + ... + 34578.

It is an arithmetic number, because the mean of its divisors is an integer number (20331360).

Almost surely, 2^261640916 is an apocalyptic number.

It is an amenable number.

261640916 is a deficient number, since it is larger than the sum of its proper divisors (226311724).

261640916 is a wasteful number, since it uses less digits than its factorization.

261640916 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60583 (or 60581 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 35.

The square root of 261640916 is about 16175.3181112459. The cubic root of 261640916 is about 639.5903270112.

The spelling of 261640916 in words is "two hundred sixty-one million, six hundred forty thousand, nine hundred sixteen".