28138319 has 4 divisors (see below), whose sum is σ = 30696360. Its totient is φ = 25580280.

The previous prime is 28138307. The next prime is 28138321. The reversal of 28138319 is 91383182.

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

It is not a de Polignac number, because 28138319 - 2⁴ = 28138303 is a prime.

It is a super-2 number, since 2×28138319² = 1583529992291522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28138379) 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, 1279004 + ... + 1279025.

It is an arithmetic number, because the mean of its divisors is an integer number (7674090).

Almost surely, 2^28138319 is an apocalyptic number.

28138319 is a deficient number, since it is larger than the sum of its proper divisors (2558041).

28138319 is a wasteful number, since it uses less digits than its factorization.

28138319 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2558040.

The product of its digits is 10368, while the sum is 35.

The square root of 28138319 is about 5304.5564376298. The cubic root of 28138319 is about 304.1580974463.

The spelling of 28138319 in words is "twenty-eight million, one hundred thirty-eight thousand, three hundred nineteen".