28120071 has 24 divisors (see below), whose sum is σ = 43855344. Its totient is φ = 15980160.

The previous prime is 28120039. The next prime is 28120073. The reversal of 28120071 is 17002182.

It is not a de Polignac number, because 28120071 - 2⁵ = 28120039 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28120073) 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 23 ways as a sum of consecutive naturals, for example, 33841 + ... + 34661.

It is an arithmetic number, because the mean of its divisors is an integer number (1827306).

Almost surely, 2^28120071 is an apocalyptic number.

28120071 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

28120071 is a deficient number, since it is larger than the sum of its proper divisors (15735273).

28120071 is a wasteful number, since it uses less digits than its factorization.

28120071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1071 (or 1064 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 21.

The square root of 28120071 is about 5302.8361279602. The cubic root of 28120071 is about 304.0923333045.

The spelling of 28120071 in words is "twenty-eight million, one hundred twenty thousand, seventy-one".