28772138 has 8 divisors (see below), whose sum is σ = 43189860. Its totient is φ = 14375520.

The previous prime is 28772077. The next prime is 28772141. The reversal of 28772138 is 83127782.

It can be written as a sum of positive squares in 2 ways, for example, as 24433249 + 4338889 = 4943^2 + 2083^2 .

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

It is a nialpdrome in base 12.

It is an unprimeable number.

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, 1253 + ... + 7688.

Almost surely, 2^28772138 is an apocalyptic number.

28772138 is a deficient number, since it is larger than the sum of its proper divisors (14417722).

28772138 is a wasteful number, since it uses less digits than its factorization.

28772138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10552.

The product of its digits is 37632, while the sum is 38.

The square root of 28772138 is about 5363.9666292773. The cubic root of 28772138 is about 306.4248942431.

The spelling of 28772138 in words is "twenty-eight million, seven hundred seventy-two thousand, one hundred thirty-eight".