28157823 has 6 divisors (see below), whose sum is σ = 40672424. Its totient is φ = 18771876.

The previous prime is 28157821. The next prime is 28157863. The reversal of 28157823 is 32875182.

28157823 is a `hidden beast` number, since 2 + 81 + 578 + 2 + 3 = 666.

It is not a de Polignac number, because 28157823 - 2¹ = 28157821 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 (28157821) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1564315 + ... + 1564332.

Almost surely, 2^28157823 is an apocalyptic number.

28157823 is a deficient number, since it is larger than the sum of its proper divisors (12514601).

28157823 is a wasteful number, since it uses less digits than its factorization.

28157823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3128653 (or 3128650 counting only the distinct ones).

The product of its digits is 26880, while the sum is 36.

The square root of 28157823 is about 5306.3945386675. The cubic root of 28157823 is about 304.2283566707.

The spelling of 28157823 in words is "twenty-eight million, one hundred fifty-seven thousand, eight hundred twenty-three".