28173994 has 4 divisors (see below), whose sum is σ = 42260994. Its totient is φ = 14086996.

The previous prime is 28173991. The next prime is 28174019. The reversal of 28173994 is 49937182.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 17850625 + 10323369 = 4225^2 + 3213^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 28173994.

It is not an unprimeable number, because it can be changed into a prime (28173991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7043497 + ... + 7043500.

Almost surely, 2^28173994 is an apocalyptic number.

28173994 is a deficient number, since it is larger than the sum of its proper divisors (14087000).

28173994 is a wasteful number, since it uses less digits than its factorization.

28173994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14086999.

The product of its digits is 108864, while the sum is 43.

The square root of 28173994 is about 5307.9180475964. The cubic root of 28173994 is about 304.2865848378.

The spelling of 28173994 in words is "twenty-eight million, one hundred seventy-three thousand, nine hundred ninety-four".