261205728 has 48 divisors (see below), whose sum is σ = 783619200. Its totient is φ = 74630016.

The previous prime is 261205723. The next prime is 261205739. The reversal of 261205728 is 827502162.

261205728 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261205723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 193678 + ... + 195021.

It is an arithmetic number, because the mean of its divisors is an integer number (16325400).

Almost surely, 2^261205728 is an apocalyptic number.

261205728 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

261205728 is an abundant number, since it is smaller than the sum of its proper divisors (522413472).

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

261205728 is a wasteful number, since it uses less digits than its factorization.

261205728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 388719 (or 388711 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 33.

The square root of 261205728 is about 16161.8602889643. The cubic root of 261205728 is about 639.2355194827.

The spelling of 261205728 in words is "two hundred sixty-one million, two hundred five thousand, seven hundred twenty-eight".