28123491 has 16 divisors (see below), whose sum is σ = 43314048. Its totient is φ = 16041600.

The previous prime is 28123489. The next prime is 28123493. The reversal of 28123491 is 19432182.

It is an interprime number because it is at equal distance from previous prime (28123489) and next prime (28123493).

It is not a de Polignac number, because 28123491 - 2¹ = 28123489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28123493) 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, 24505 + ... + 25626.

It is an arithmetic number, because the mean of its divisors is an integer number (2707128).

Almost surely, 2^28123491 is an apocalyptic number.

28123491 is a deficient number, since it is larger than the sum of its proper divisors (15190557).

28123491 is a wasteful number, since it uses less digits than its factorization.

28123491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50162.

The product of its digits is 3456, while the sum is 30.

The square root of 28123491 is about 5303.1585871064. The cubic root of 28123491 is about 304.1046608412.

The spelling of 28123491 in words is "twenty-eight million, one hundred twenty-three thousand, four hundred ninety-one".