28171147 has 4 divisors (see below), whose sum is σ = 28334160. Its totient is φ = 28008136.

The previous prime is 28171123. The next prime is 28171153. The reversal of 28171147 is 74117182.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 74117182 = 2 ⋅37058591.

It is a cyclic number.

It is not a de Polignac number, because 28171147 - 2¹⁵ = 28138379 is a prime.

It is a super-2 number, since 2×28171147² = 1587227046591218, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28171747) 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, 81247 + ... + 81592.

It is an arithmetic number, because the mean of its divisors is an integer number (7083540).

Almost surely, 2^28171147 is an apocalyptic number.

28171147 is a deficient number, since it is larger than the sum of its proper divisors (163013).

28171147 is a wasteful number, since it uses less digits than its factorization.

28171147 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163012.

The product of its digits is 3136, while the sum is 31.

The square root of 28171147 is about 5307.6498565749. The cubic root of 28171147 is about 304.2763350416.

The spelling of 28171147 in words is "twenty-eight million, one hundred seventy-one thousand, one hundred forty-seven".