28973138 has 12 divisors (see below), whose sum is σ = 45868590. Its totient is φ = 13723776.

The previous prime is 28973129. The next prime is 28973143. The reversal of 28973138 is 83137982.

It can be written as a sum of positive squares in only one way, i.e., 28912129 + 61009 = 5377^2 + 247^2 .

It is a junction number, because it is equal to n+sod(n) for n = 28973095 and 28973104.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 19343 + ... + 20786.

Almost surely, 2^28973138 is an apocalyptic number.

28973138 is a deficient number, since it is larger than the sum of its proper divisors (16895452).

28973138 is a wasteful number, since it uses less digits than its factorization.

28973138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40169 (or 40150 counting only the distinct ones).

The product of its digits is 72576, while the sum is 41.

The square root of 28973138 is about 5382.6701552297. The cubic root of 28973138 is about 307.1367928340.

It can be divided in two parts, 289731 and 38, that multiplied together give a triangular number (11009778 = T₄₆₉₂).

The spelling of 28973138 in words is "twenty-eight million, nine hundred seventy-three thousand, one hundred thirty-eight".