28123545261 has 16 divisors (see below), whose sum is σ = 43072470144. Its totient is φ = 15989018304.

The previous prime is 28123545259. The next prime is 28123545341. The reversal of 28123545261 is 16254532182.

It is not a de Polignac number, because 28123545261 - 2¹ = 28123545259 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28123545221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3394890 + ... + 3403163.

It is an arithmetic number, because the mean of its divisors is an integer number (2692029384).

Almost surely, 2^28123545261 is an apocalyptic number.

28123545261 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

28123545261 is a deficient number, since it is larger than the sum of its proper divisors (14948924883).

28123545261 is a wasteful number, since it uses less digits than its factorization.

28123545261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6798260.

The product of its digits is 115200, while the sum is 39.

The spelling of 28123545261 in words is "twenty-eight billion, one hundred twenty-three million, five hundred forty-five thousand, two hundred sixty-one".