28981538 has 8 divisors (see below), whose sum is σ = 43506588. Its totient is φ = 14479344.

The previous prime is 28981531. The next prime is 28981571. The reversal of 28981538 is 83518982.

It can be written as a sum of positive squares in 2 ways, for example, as 28697449 + 284089 = 5357^2 + 533^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (28981531) 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, 2081 + ... + 7892.

Almost surely, 2^28981538 is an apocalyptic number.

28981538 is a deficient number, since it is larger than the sum of its proper divisors (14525050).

28981538 is a wasteful number, since it uses less digits than its factorization.

28981538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11428.

The product of its digits is 138240, while the sum is 44.

The square root of 28981538 is about 5383.4503805645. The cubic root of 28981538 is about 307.1664720466.

The spelling of 28981538 in words is "twenty-eight million, nine hundred eighty-one thousand, five hundred thirty-eight".