28919871 has 24 divisors (see below), whose sum is σ = 42673904. Its totient is φ = 18869760.

The previous prime is 28919867. The next prime is 28919893. The reversal of 28919871 is 17891982.

It is not a de Polignac number, because 28919871 - 2² = 28919867 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28919831) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 136956 + ... + 137166.

Almost surely, 2^28919871 is an apocalyptic number.

28919871 is a deficient number, since it is larger than the sum of its proper divisors (13754033).

28919871 is a wasteful number, since it uses less digits than its factorization.

28919871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 471 (or 468 counting only the distinct ones).

The product of its digits is 72576, while the sum is 45.

The square root of 28919871 is about 5377.7198699821. The cubic root of 28919871 is about 306.9484541058.

The spelling of 28919871 in words is "twenty-eight million, nine hundred nineteen thousand, eight hundred seventy-one".