28272431 has 4 divisors (see below), whose sum is σ = 30842664. Its totient is φ = 25702200.

The previous prime is 28272401. The next prime is 28272443. The reversal of 28272431 is 13427282.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28272431 - 2¹⁴ = 28256047 is a prime.

It is a super-2 number, since 2×28272431² = 1598660709299522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28272394 and 28272403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28272401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1285100 + ... + 1285121.

It is an arithmetic number, because the mean of its divisors is an integer number (7710666).

Almost surely, 2^28272431 is an apocalyptic number.

28272431 is a deficient number, since it is larger than the sum of its proper divisors (2570233).

28272431 is a wasteful number, since it uses less digits than its factorization.

28272431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2570232.

The product of its digits is 5376, while the sum is 29.

The square root of 28272431 is about 5317.1826186431. The cubic root of 28272431 is about 304.6405547887.

The spelling of 28272431 in words is "twenty-eight million, two hundred seventy-two thousand, four hundred thirty-one".