28391671 has 16 divisors (see below), whose sum is σ = 35889408. Its totient is φ = 21816000.

The previous prime is 28391663. The next prime is 28391677. The reversal of 28391671 is 17619382.

It is a cyclic number.

It is not a de Polignac number, because 28391671 - 2³ = 28391663 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28391671.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28391677) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3096 + ... + 8146.

It is an arithmetic number, because the mean of its divisors is an integer number (2243088).

Almost surely, 2^28391671 is an apocalyptic number.

28391671 is a deficient number, since it is larger than the sum of its proper divisors (7497737).

28391671 is a wasteful number, since it uses less digits than its factorization.

28391671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5142.

The product of its digits is 18144, while the sum is 37.

The square root of 28391671 is about 5328.3835259861. The cubic root of 28391671 is about 305.0682316218.

The spelling of 28391671 in words is "twenty-eight million, three hundred ninety-one thousand, six hundred seventy-one".