28128558261 has 32 divisors (see below), whose sum is σ = 38591078400. Its totient is φ = 18215708544.

The previous prime is 28128558223. The next prime is 28128558281. The reversal of 28128558261 is 16285582182.

It is not a de Polignac number, because 28128558261 - 2⁶ = 28128558197 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28128558261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28128558281) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 14112681 + ... + 14114673.

It is an arithmetic number, because the mean of its divisors is an integer number (1205971200).

Almost surely, 2^28128558261 is an apocalyptic number.

It is an amenable number.

28128558261 is a deficient number, since it is larger than the sum of its proper divisors (10462520139).

28128558261 is a wasteful number, since it uses less digits than its factorization.

28128558261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2745.

The product of its digits is 614400, while the sum is 48.

The spelling of 28128558261 in words is "twenty-eight billion, one hundred twenty-eight million, five hundred fifty-eight thousand, two hundred sixty-one".