28190818 has 8 divisors (see below), whose sum is σ = 43429212. Its totient is φ = 13714416.

The previous prime is 28190809. The next prime is 28190837. The reversal of 28190818 is 81809182.

It can be written as a sum of positive squares in 2 ways, for example, as 28164249 + 26569 = 5307^2 + 163^2 .

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

It is a Harshad number since it is a multiple of its sum of digits (37).

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 3 ways as a sum of consecutive naturals, for example, 190405 + ... + 190552.

Almost surely, 2^28190818 is an apocalyptic number.

28190818 is a deficient number, since it is larger than the sum of its proper divisors (15238394).

28190818 is a wasteful number, since it uses less digits than its factorization.

28190818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 380996.

The product of its (nonzero) digits is 9216, while the sum is 37.

The square root of 28190818 is about 5309.5026132398. The cubic root of 28190818 is about 304.3471406687.

The spelling of 28190818 in words is "twenty-eight million, one hundred ninety thousand, eight hundred eighteen".