28383381 has 18 divisors (see below), whose sum is σ = 44396898. Its totient is φ = 17465760.

The previous prime is 28383371. The next prime is 28383389. The reversal of 28383381 is 18338382.

It can be written as a sum of positive squares in 3 ways, for example, as 1602756 + 26780625 = 1266^2 + 5175^2 .

It is not a de Polignac number, because 28383381 - 2⁹ = 28382869 is a prime.

It is a super-2 number, since 2×28383381² = 1611232633982322, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28383389) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 7810 + ... + 10851.

Almost surely, 2^28383381 is an apocalyptic number.

It is an amenable number.

28383381 is a deficient number, since it is larger than the sum of its proper divisors (16013517).

28383381 is a wasteful number, since it uses less digits than its factorization.

28383381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18693 (or 18677 counting only the distinct ones).

The product of its digits is 27648, while the sum is 36.

The square root of 28383381 is about 5327.6055597238. The cubic root of 28383381 is about 305.0385367414.

The spelling of 28383381 in words is "twenty-eight million, three hundred eighty-three thousand, three hundred eighty-one".