28891075 has 12 divisors (see below), whose sum is σ = 37932840. Its totient is φ = 21752960.

The previous prime is 28891073. The next prime is 28891081. The reversal of 28891075 is 57019882.

It is not a de Polignac number, because 28891075 - 2¹ = 28891073 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28891073) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 33565 + ... + 34414.

It is an arithmetic number, because the mean of its divisors is an integer number (3161070).

Almost surely, 2^28891075 is an apocalyptic number.

28891075 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

28891075 is a deficient number, since it is larger than the sum of its proper divisors (9041765).

28891075 is a wasteful number, since it uses less digits than its factorization.

28891075 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68006 (or 68001 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 40.

The square root of 28891075 is about 5375.0418603021. The cubic root of 28891075 is about 306.8465423674.

The spelling of 28891075 in words is "twenty-eight million, eight hundred ninety-one thousand, seventy-five".