261728394 has 8 divisors (see below), whose sum is σ = 523456800. Its totient is φ = 87242796.

The previous prime is 261728371. The next prime is 261728419. The reversal of 261728394 is 493827162.

261728394 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

261728394 is an admirable number.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21810694 + ... + 21810705.

It is an arithmetic number, because the mean of its divisors is an integer number (65432100).

Almost surely, 2^261728394 is an apocalyptic number.

261728394 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

261728394 is a wasteful number, since it uses less digits than its factorization.

261728394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43621404.

The product of its digits is 145152, while the sum is 42.

The square root of 261728394 is about 16178.0219433650. The cubic root of 261728394 is about 639.6616000740.

The spelling of 261728394 in words is "two hundred sixty-one million, seven hundred twenty-eight thousand, three hundred ninety-four".