28861601 has 4 divisors (see below), whose sum is σ = 29334804. Its totient is φ = 28388400.

The previous prime is 28861579. The next prime is 28861603. The reversal of 28861601 is 10616882.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 10616882 = 2 ⋅5308441.

It can be written as a sum of positive squares in 2 ways, for example, as 12418576 + 16443025 = 3524^2 + 4055^2 .

It is a cyclic number.

It is not a de Polignac number, because 28861601 - 2⁶ = 28861537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28861603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 236510 + ... + 236631.

It is an arithmetic number, because the mean of its divisors is an integer number (7333701).

Almost surely, 2^28861601 is an apocalyptic number.

It is an amenable number.

28861601 is a deficient number, since it is larger than the sum of its proper divisors (473203).

28861601 is an equidigital number, since it uses as much as digits as its factorization.

28861601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 473202.

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 28861601 is about 5372.2994145896. The cubic root of 28861601 is about 306.7421609714.

The spelling of 28861601 in words is "twenty-eight million, eight hundred sixty-one thousand, six hundred one".