28871081 has 4 divisors (see below), whose sum is σ = 28916352. Its totient is φ = 28825812.

The previous prime is 28871071. The next prime is 28871111. The reversal of 28871081 is 18017882.

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-28871081 is a prime.

It is a super-2 number, since 2×28871081² = 1667078636217122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28871021) 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, 21665 + ... + 22958.

It is an arithmetic number, because the mean of its divisors is an integer number (7229088).

Almost surely, 2^28871081 is an apocalyptic number.

It is an amenable number.

28871081 is a deficient number, since it is larger than the sum of its proper divisors (45271).

28871081 is an equidigital number, since it uses as much as digits as its factorization.

28871081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45270.

The product of its (nonzero) digits is 7168, while the sum is 35.

The square root of 28871081 is about 5373.1816459152. The cubic root of 28871081 is about 306.7757418916.

The spelling of 28871081 in words is "twenty-eight million, eight hundred seventy-one thousand, eighty-one".