28715081 has 4 divisors (see below), whose sum is σ = 28941312. Its totient is φ = 28488852.

The previous prime is 28715051. The next prime is 28715087. The reversal of 28715081 is 18051782.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28715081 is a prime.

It is a super-2 number, since 2×28715081² = 1649111753673122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28715087) 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, 112925 + ... + 113178.

It is an arithmetic number, because the mean of its divisors is an integer number (7235328).

Almost surely, 2^28715081 is an apocalyptic number.

It is an amenable number.

28715081 is a deficient number, since it is larger than the sum of its proper divisors (226231).

28715081 is a wasteful number, since it uses less digits than its factorization.

28715081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 226230.

The product of its (nonzero) digits is 4480, while the sum is 32.

The square root of 28715081 is about 5358.6454445130. The cubic root of 28715081 is about 306.2222067794. Note that the first 4 decimals are identical.

The spelling of 28715081 in words is "twenty-eight million, seven hundred fifteen thousand, eighty-one".