28391427 has 12 divisors (see below), whose sum is σ = 41108184. Its totient is φ = 18882240.

The previous prime is 28391423. The next prime is 28391477. The reversal of 28391427 is 72419382.

It is not a de Polignac number, because 28391427 - 2² = 28391423 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28391391 and 28391400.

It is not an unprimeable number, because it can be changed into a prime (28391423) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 427 + ... + 7547.

It is an arithmetic number, because the mean of its divisors is an integer number (3425682).

Almost surely, 2^28391427 is an apocalyptic number.

28391427 is a deficient number, since it is larger than the sum of its proper divisors (12716757).

28391427 is a wasteful number, since it uses less digits than its factorization.

28391427 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7570 (or 7567 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 28391427 is about 5328.3606296871. The cubic root of 28391427 is about 305.0673576934.

The spelling of 28391427 in words is "twenty-eight million, three hundred ninety-one thousand, four hundred twenty-seven".