28126129 has 4 divisors (see below), whose sum is σ = 28247076. Its totient is φ = 28005184.

The previous prime is 28126121. The next prime is 28126141. The reversal of 28126129 is 92162182.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10080625 + 18045504 = 3175^2 + 4248^2 .

It is a cyclic number.

It is not a de Polignac number, because 28126129 - 2³ = 28126121 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28126129.

It is not an unprimeable number, because it can be changed into a prime (28126121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 60124 + ... + 60589.

It is an arithmetic number, because the mean of its divisors is an integer number (7061769).

Almost surely, 2^28126129 is an apocalyptic number.

It is an amenable number.

28126129 is a deficient number, since it is larger than the sum of its proper divisors (120947).

28126129 is a wasteful number, since it uses less digits than its factorization.

28126129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120946.

The product of its digits is 3456, while the sum is 31.

The square root of 28126129 is about 5303.4073009717. The cubic root of 28126129 is about 304.1141689426.

The spelling of 28126129 in words is "twenty-eight million, one hundred twenty-six thousand, one hundred twenty-nine".