28738331 has 4 divisors (see below), whose sum is σ = 28782600. Its totient is φ = 28694064.

The previous prime is 28738321. The next prime is 28738343. The reversal of 28738331 is 13383782.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13383782 = 2 ⋅6691891.

It is a cyclic number.

It is not a de Polignac number, because 28738331 - 2²² = 24544027 is a prime.

It is a super-2 number, since 2×28738331² = 1651783337331122, 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 = 28738291 and 28738300.

It is not an unprimeable number, because it can be changed into a prime (28738301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21146 + ... + 22463.

It is an arithmetic number, because the mean of its divisors is an integer number (7195650).

Almost surely, 2^28738331 is an apocalyptic number.

28738331 is a deficient number, since it is larger than the sum of its proper divisors (44269).

28738331 is an equidigital number, since it uses as much as digits as its factorization.

28738331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44268.

The product of its digits is 24192, while the sum is 35.

The square root of 28738331 is about 5360.8143970856. The cubic root of 28738331 is about 306.3048317205.

The spelling of 28738331 in words is "twenty-eight million, seven hundred thirty-eight thousand, three hundred thirty-one".