261728404 has 18 divisors (see below), whose sum is σ = 532804650. Its totient is φ = 112169232.

The previous prime is 261728371. The next prime is 261728419. The reversal of 261728404 is 404827162.

It is a happy number.

261728404 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 only one way, i.e., 256064004 + 5664400 = 16002^2 + 2380^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 261728404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 667479 + ... + 667870.

Almost surely, 2^261728404 is an apocalyptic number.

It is an amenable number.

261728404 is an abundant number, since it is smaller than the sum of its proper divisors (271076246).

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

261728404 is a wasteful number, since it uses less digits than its factorization.

261728404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1335367 (or 1335358 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 34.

The square root of 261728404 is about 16178.0222524263. The cubic root of 261728404 is about 639.6616082206.

The spelling of 261728404 in words is "two hundred sixty-one million, seven hundred twenty-eight thousand, four hundred four".