28043431 has 4 divisors (see below), whose sum is σ = 30200632. Its totient is φ = 25886232.

The previous prime is 28043423. The next prime is 28043441. The reversal of 28043431 is 13434082.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28043431 - 2³ = 28043423 is a prime.

It is a super-2 number, since 2×28043431² = 1572868044503522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28043396 and 28043405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28043401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1078581 + ... + 1078606.

It is an arithmetic number, because the mean of its divisors is an integer number (7550158).

Almost surely, 2^28043431 is an apocalyptic number.

28043431 is a deficient number, since it is larger than the sum of its proper divisors (2157201).

28043431 is a wasteful number, since it uses less digits than its factorization.

28043431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2157200.

The product of its (nonzero) digits is 2304, while the sum is 25.

The square root of 28043431 is about 5295.6048757437. The cubic root of 28043431 is about 303.8158185764.

The spelling of 28043431 in words is "twenty-eight million, forty-three thousand, four hundred thirty-one".