28240771 has 4 divisors (see below), whose sum is σ = 30413152. Its totient is φ = 26068392.

The previous prime is 28240739. The next prime is 28240787. The reversal of 28240771 is 17704282.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17704282 = 2 ⋅8852141.

It is a cyclic number.

It is not a de Polignac number, because 28240771 - 2⁵ = 28240739 is a prime.

It is a super-2 number, since 2×28240771² = 1595082293348882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28240571) 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, 1086171 + ... + 1086196.

It is an arithmetic number, because the mean of its divisors is an integer number (7603288).

Almost surely, 2^28240771 is an apocalyptic number.

28240771 is a deficient number, since it is larger than the sum of its proper divisors (2172381).

28240771 is a wasteful number, since it uses less digits than its factorization.

28240771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2172380.

The product of its (nonzero) digits is 6272, while the sum is 31.

The square root of 28240771 is about 5314.2046441589. The cubic root of 28240771 is about 304.5267982415.

The spelling of 28240771 in words is "twenty-eight million, two hundred forty thousand, seven hundred seventy-one".