28016431 has 4 divisors (see below), whose sum is σ = 29491000. Its totient is φ = 26541864.

The previous prime is 28016419. The next prime is 28016441. The reversal of 28016431 is 13461082.

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 28016431 - 2¹¹ = 28014383 is a prime.

It is a super-2 number, since 2×28016431² = 1569840811955522, 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 = 28016396 and 28016405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28016411) 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, 737256 + ... + 737293.

It is an arithmetic number, because the mean of its divisors is an integer number (7372750).

Almost surely, 2^28016431 is an apocalyptic number.

28016431 is a deficient number, since it is larger than the sum of its proper divisors (1474569).

28016431 is a wasteful number, since it uses less digits than its factorization.

28016431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1474568.

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 28016431 is about 5293.0549779877. The cubic root of 28016431 is about 303.7182834220.

The spelling of 28016431 in words is "twenty-eight million, sixteen thousand, four hundred thirty-one".