28138031 has 8 divisors (see below), whose sum is σ = 29694720. Its totient is φ = 26588952.

The previous prime is 28138027. The next prime is 28138037. The reversal of 28138031 is 13083182.

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

It is a cyclic number.

It is not a de Polignac number, because 28138031 - 2² = 28138027 is a prime.

It is a super-2 number, since 2×28138031² = 1583497577113922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28138037) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6746 + ... + 10088.

It is an arithmetic number, because the mean of its divisors is an integer number (3711840).

Almost surely, 2^28138031 is an apocalyptic number.

28138031 is a deficient number, since it is larger than the sum of its proper divisors (1556689).

28138031 is a wasteful number, since it uses less digits than its factorization.

28138031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3805.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 28138031 is about 5304.5292910870. The cubic root of 28138031 is about 304.1570597412.

The spelling of 28138031 in words is "twenty-eight million, one hundred thirty-eight thousand, thirty-one".